Prosramme of Studies
For The High School
Guide for Practical and
... IN ...
Additional copies of this Bulletin may be had from the
General Office of the Department of Education at 20 cents
EDMONTON: Printed by A. Shnitka, King's Printer.
"Laboratory work" in any one of the senior science courses
is NOT a course in itself, separate and distinct from a course in
theory. It is not designed to produce research students, but
rather to illuminate the facts and theory of the subject, and pro-
vide, along with other activities, some meaningful experience for
the student that may facilitate his comprehension. Teaching and
practical work must therefore go hand in hand, and be kept in
step. Failure to synchronize theory and practical work defeats
the purpose of a course in science. Students who memorize the
theory without having had the benefit of practical exercises can-
not meet the requirements of any science course ; but, on the other
hand, there can be little justification for a procedure that permits
the practical work to outrun the theory, or that concentrates the
practical work in a few weeks at the end of the term.
The outlines for practical work in chemistry, physics and
biology given in this Tbulletin are suggestive rather than prescrip-
tive. More exercises may be required to meet the needs of a par-
ticular class; and other and better exercises may be devised by
the teacher in consultation with his students. The suggested out-
lines will, however, save some of the teachers' and students' time.
This bulletin is to be used as a guide to practical and experi-
mental work and not as a student workbook. That is, students
should not write answers to questions, give observations or tabu-
late results in this book but should be required to make all nota-
tions in a suitable notebook.
It is recommended that, wherever possible, experiments be
performed by groups of two and that each student be required to
keep a record of the experiments carried out. Written reports on
selected experiments should be done in an approved manner, us-
ing carefully-labelled diagrams, equations or statements of basic
scientific principles when any or all of these will add to the quality
of the report. These written reports should be kept in a separate
notebook, looseleaf preferred.
UNIVERSITY OF ALBERTA
THE SCIENCE LABORATORY
Some of the statements made in the introductory section of
Bulletin 5a may be appropriately repeated here. It was men-
tioned, for example, that some schools do not have the use of an
extra room for a science laboratory; hence all practical and ex-
perimental work has to be done in the regular classroom. In such
cases, the comments made concerning the science room should be
Where a separate room for laboratory work is available, it is
best that it be conveniently located in the school building, well
lighted and ventilated, supplied with good apparatus, adequately
furnished and given proper care.
ATTENTION TO ENGLISH
The suggestions found in Bulletin 5a under the heading, "The
Importance and place of English in the Science Courses", are
also appropriate for this bulletin. In the section referred to, it
was stated that students of science should be able to participate
successfully in certain science activities that are common in their
school and everyday lives. The activities named are:
2. Taking part in discussions,
3. Preparing and making reports,
4. Giving descriptions and explanations.
All these activities are present in a well-balanced science
course. In laboratory work particular attention should be given
to activities 3 and 4. In these activities, several particular
abilities will have to receive special attention, such as mastery
of vocabulary, spelling, punctuation and effective expression.
Where basic principles are involved, they should be stated
accurately and, in written reports, placed in a prominent position.
In all cases, the instructor is at liberty to devise methods of
procedure for his students that will meet desired objectives and
requirements of the respective courses.
The experimental work in Physics 2 will consist partly of ex-
periments demonstrated by the teacher and partly of experiments
designed for individual work or for groups of two or three stu-
dents working together.
The twenty experiments in this outline have been selected for
individual work on the basis that each requires some quantitative
observations and involves some definite calculations leading to a
specific result. Completed experiments, with a reasonable degree
of accuracy, should be expected of all students.
The experiments are in two groups, the first ten dealing with
Mechanics and Heat, the second ten dealing with Magnetism and
Electricity. A minimum of seven in each group should be done
by each student.
Owing to the fact that much of the apparatus for these ex-
periments is expensive, it is suggested that only one or two sets
of apparatus for each experiment should be provided. This will
make it necessary for groups to perform the experiments in
The list of apparatus provided below is based on the assump-
tion that many of the experiments will be running concurrently
where larger classes are involved ; hence the necessity for several
of such instruments as ammeters and voltmeters. An adequate
supply of such equipment should be built up in each school over a
period of years. This list does not include demonstration equip-
ment. There is practically no limit to the amount of equipment
a teacher will find useful in teaching this course. It can be added
to indefinitely, but much of it may be improvised or constructed
by students at home or in the school shop.
List of Apparatus for Physics 2
3 spring balances (250 gm.)
3 spring balances (2000 gm.)
*1 spring balance (15 kgm.)
*1 parallelogram of forces board
11" perforated metal ball
3 large retort stands and clamps (iron)
1 wooden stand and clamp
1 board for friction experiments
1 set of kilogram weights on hook
1 set of gram weights on hook
1 wheel and axle
1 metre stick
1 inclined plane and car
3 insulated calorimeters
6 thermometers (centigrade)
2 thermometers (Fahrenheit)
3 physical balances
3 sets of metric weights
1 aluminum block for specific heat experiment
*1 Liebig's condenser
*1 distilling flask
*1 boiler for heat experiments
2 water traps
1 Regnault's dewpoint hygrometer
1 Wet and dry bulb hygrometer
6 bar magnets (6" long)
1 horseshoe magnet
1 box of fine iron filings
1 roll of blue print paper
1 grooved board for bar magnets
1 demonstration Voltaic cell
6 zinc elements for the above
4 copper elements for the above
2 carhon elements for the above
3 Daniell cells
3 dry cells
3 voltmeters (low range, D.C. graduated in tenths)
3 ammeters (low range, D.C. graduated in tenths)
*1 voltmeter (A.C. 0-150 volts)
*1 ammeter (A.C. 0-10 amps.)
1 resistance box (plug-in type)
1 resistance box (dial type)
1 set of assorted standard resistances
1 variable resistance (0-3 ohms)
1 storage battery (6 volts)
6 knife switches (s.p.s.t.)
1 Wheatstone bridge (slide wire type)
1 D'Arsonval type galvanometer
12 pietenpol connectors
6 test clips
1 mercury barometer
1 galvanoscope (multiple coil type)
6 small compass needles (enclosed)
1 demonstration compass needle (open)
*1 St. Louis type demonstration electric motor
*3 40-watt lamps (Mazda)
*1 25-watt lamp (Mazda)
*1 60-watt lamp (Mazda)
*1 100- watt lamp (Mazda)
*1 16-c.p. carbon lamp
*1 32-c.p. carbon lamp
1 set primary and secondary coils with core.
In addition to the above, assorted beakers, flasks, test tubes,
measuring cylinders, glass tubing, rubber tubing, rubber corks,
tripods, bunsen burners or spirit lamps, reagent bottles, battery
jars, porous cups, wire gauze and other chemical equipment will
Special chemicals for these experiments include :
Ethyl alcohol (95%)
*The apparatus marked with an asterisk is less essential or
expensive equipment which is required for only one experiment
and could be omitted.
The Parallelogram of Forces
Object: To demonstrate the proposition known as the paral-
lelogram of forces, and to calculate the equilibriant of two forces
acting at any angle.
Reference: ''Modern Physics," Sections 131-136. Study the
definitions of ''Resultant of two Forces acting at any angle," and
"Equilibriant of two or more forces."
Apparatus: Three spring balances graduated in grams, a
small iron ring (diameter 1")> string, drawing paper, thumb
tacks, either three 3" nails or perforated board and pins as listed
in science catalogues.
Procedure: If the prepared board is available, tie three
lengths of string to the iron ring, place the three pins in holes at
the extreme ends of the board and adjust the three spring bal-
ances on the board so that when the three strings are tied to their
hooks and their rings are placed over the pins they will each
reigister a tension at about the middle of their scales.
If the board is not available, use the three 3" nails driven
firmly into an old table or bench so that they form a triangle with
sides about three feet long. The spring balances are attached to
these nails and to the iron ring by means of lengths of string,
with the iron ring approximately in the centre of the triangle.
Place a sheet of drawing paper under the strings with the iron
ring in the centre and attach to the board or table by means of
tacks. Make sure that the balances are stretched with as little
friction as possible against the board or pins. Using a set square,
mark two points vertically below each string, one at each end, so
that when these points are joined with straight lines they will
exactly represent the direction of each string.
Now read each spring balance as accurately as possible and
record its value in grams on the paper along the string attached
to it. Remove the balances from the pins, join up the points on
the paper so that they meet in a point.
Along two of the lines mark off lengths proportional to the
readings of the spring balances. A suitable scale might be 1 cm.
to represent 20 gm. Taking these two lengths as the two ad-
jacent sides of a parallelogram, complete the parallelogram using
a compass to mark off equal opposite sides.
Draw the diagonal of the parallelogram, measure its length
in centimetres and express it as a force in grams on the same
scale as you used for the sides of the parallelogram.
Results: Is the diagonal of your parallelogram in the same
straight line as the line representing the pull of the third balance?
If your work was done accurately and the balances registered cor-
rectly with the minimum of friction, this should be the case.
Does the length of the diagonal in centimeters represent the
same value in grams as the third balance?
Letter your diagram ABCD etc., and state in the lower right-
hand corner of the paper which lines represent which forces,
which is the resultant force and which is the equilibriant. Write
a statement in ink of the proposition which you have thus
The Simple Pendulum
Object: To study the laws governing the oscillation of a pen-
dulum and to find the value of g, the acceleration due to gravity.
Reference: ^'Modern Physics,'* Sections 162-166. Study the
definitions of ''single vibration," ''complete vibration," "period,"
"amplitude of vibration."
Apparatus: About 4 feet of strong thread, one inch metal ball
perforated through the centre, or other suitable pendulum bob,
clamp, stop watch or metronome. An ordinary watch with a sec-
onds hand may be used if a stop watch or metronome is not
Procedure: (a) Tie the thread to the metal ball and secure
the other end by means of a clamp, adjusting the length of the
pendulum so that it is exactly one meter from the point of sus-
pension to the centre of the bob. Pull the bob to one side through
a small arc, not more than three inches, and release it. When it
is swinging uniformly, take the time in seconds for it to make 30
single vibrations. Two students working together can do this
quite accurately with an ordinary watch if one watches the pen-
dulum and gives the time for starting and stopping the count,
whilst the other observes the seconds hand of the watch.
Repeat the experiment with the pendulum swinging over a
larger arc, say, six inches, and again with an arc of about one
foot. Keep a record of your results.
(b) Shorten the thread so that the effective length of the
pendulum is 25 cm., and determine the average period of oscilla-
tion; i.e., the time for one complete vibration of the pendulum.
Use a small arc and take the average time for twenty complete
swings, using several tries. Record the results.
(c) Repeat the experiment using a pendulum with an effec-
tive length of 64 cm. Record the average value for the period of
Tabulate your results from experiment (a) thus:
No. of single
What is the relation between the time of vibration and the
amplitude? State the result as a law. (See Section 163 of text-
Tabulate your results from experiments (b) and (c) thus :
Value of g.
How is the time of vibration related to the length of the
pendulum? State this as a law. (See Section 163 of textbook.)
Determine the value of "g'' by using the formula.
T = 2
The Coefficient of Friction
Object: To determine the coefficient of sliding friction and
to compare it with rolling friction.
Reference: ''Modern Physics," Sections 183-190. Study Sec-
tion 187 and the definition of "coefficient of friction."
Apparatus: A board 5 ft. long and 4 or 5 in. wide, preferably
of fir or other hard wood, planed and smoothed with sandpaper,
a small block of the same material about 3'' x 5" x 1", spring
balance, kilogram weights, small experimental car, string.
Procedure: (a) Insert a small hook in the centre of one end
of the wooden block, suspend it from the spring balance and
record its weight in grams. Lay the long board flat on a bench
and rub the small wooden block over it several times. Attach a
string to the hook on the block and tie the other end to the balance
as in Fig. 221 of the textbook. Pull gently on the balance and
tap on the board so that the block just starts moving. Read the
balance at this instant. Repeat several times and determine the
average force of friction. Record all readings in tabular form.
Now place a kilogram weight on the wooden block and repeat
the experiment, again recording the readings of the balance and
determining the average force of friction.
(b) Place a stop against one end of the board and lay the
wooden block on the board. Raise the other end of the board
until the block begins to slide down the slope. Note the approxi-
mate angle of repose; i.e., the greatest angle at which the block
remains in equilibrium on the inclined plane. Place a support
under the board and adjust the slope of the plane so that when
gently tapped the block will begin to slide down the slope. Meas-
ure the vertical height of the slope and the length of the base line
along the table. For accurate measurement, the slope of the
triangle must be produced and the exact point at which it meets
the table marked. The dimensions of the right-angled triangle
should be carefully recorded and the angle of the plane at the
base determined with a protractor.
(c) Lay the board flat and place the trolley car on it. Gently
raise the board at one end until the car begins to move evenly
down the slope. Determine the height and base of the triangle
so obtained as before.
Now lock the wheels of the car with a wedge and repeat the
experiment determining the dimensions of the slope down which
the car slides with locked wheels.
Results: Determine from the data of experiment (a) the
coefficient of sliding friction as worked out in Section 187 of the
Is the value the same when the block carried the kilogram
From the data of experiments (b) and (c) the coefficient
of friction may be determined by the formula,
p ^ _ Vertical height
' "~ Length of base
How do the results of experiment (a) and (b) compare?
These two methods should give approximately the same results.
The coefficient of friction may also be obtained by determin-
ing the tangent of the angle of friction. That is, if the angle
between the board and the table at the base is i, the coefficient of
friction =tan i. The results of this method should again check
with those obtained above.
From the data of experiment (c) determine the coefficient
of rolling friction and the coefficient of sliding friction. Which
is the greater ?
Tabulate the results of experiments (a), (b), and (c) in
three separate tables, setting forth the weights used, the force of
friction, the dimensions of the slopes and the calculated coeffi-
cients for each set of values.
Part A — ^The Wheel and Axle
Object: To determine the mechanical advantage of the wheel
Reference: "Modern Physics," Section 214-215. Study the
method of determining the mechanical advantage of the wheel
and axle as given in Section 214.
Apparatus: An experimental wheel and axle may be obtained
from scientific supply companies, or it may be simply constructed
by obtaining two wooden spools or cylinders, one large and the
other small, and gluing them together coaxially- Nails may be
driven into the centre of each spool to form an axle which can rest
in two short lengths of glass tubing for bearings. The wheel
and axle should turn symmetrically on these bearings which may
be lubricated with oil to reduce friction. A small hole bored
diagonally through the rim of each cylinder will provide points
of attachment for strings. A small tray to carry weights may be
made from the lid of a round can with holes bored around its rim
for the supporting wires or string.
Procedure: Set up the wheel and axle and see that it turns
without wobbling and with as little friction at the bearings as
possible. Tie a string to the small wheel or axle and pass it
around the circumference twice. To the other end of the string
tie a 500 gm. weight. Tie a string to the large wheel and pass
it around its circumference in the reverse direction to the string
around the axle. Attach the tray, previously weighed, to the
other end of this string. Now place weights in the tray until the
wheel and axle remains in equilibrium with both weights hanging
freely. Record the weights used and measure the diameters of
the wheel and axle using a pair of calipers or dividers. Record
the diameters in centimetres correct to the second decimal place.
Repeat the experiment using a 200 gm. weight and again
with a 1000 gm. weight. Record the weights needed to balance
these in each case.
Results: Determine the theoretical Mechanical Advantage of
this system from the dimensions of wheel and axle as explained
in Section 214 of the textbook. Determine the actual mechanical
advantage by dividing the weight by the effort for each experi-
ment. Compare the theoretical mechanical advantage with the
true mechanical advantage.
Tabulate results as follows :
Note: In above table W is the weight placed in the tray, w is the
weight of the tray.
Part B (optional).
Reference: "Modern Physics," Section 223.
Apparatus: Bicycle, kilogram weight, 15 kgm. spring bal-
ance, 2" tape, metre stick.
Procedure: Support the bicycle so that the back wheel will
turn freely. Measure the diameter of the rear wheel in centi-
metres and determine its circumference.
Count the number of teeth in the two sprocket wheels and
determine how many revolutions the rear wheel makes for one
complete turn of the pedals. Check this experimentally. Meas-
ure the length of the pedal arm from centre to centre of the
supporting axle. Determine the circumference of the circle
traced out by a pedal in one revolution. This will give the
distance the effort moves for one turn of the pedals. Determine
the mechanical advantage of speed by dividing the distance of
the resistance (circumference of rear wheel multiplied by the
gear ratio) by the distance of the effort. The Mechanical Advan-
tage of Force is the inverse of this. Why?
Now attach a one-kilogram weight to the tire of the rear
wheel so that it hangs down vertically below the outer circum-
ference of the wheel. A piece of 2" tape placed over the outer
circumference of the tire and supporting the weight is a good
method of doing this.
Hook the 15 kgm. spring balance to the centre of the pedal
and pull upward, taking the reading of the balance when the
pedal is in a horizontal position. Divide the resistance (1000
gm.) by the effort. This gives the actual Mechanical Advantage
Results: Tabulate all measurements and work out the actual
and theoretical values for the Mechanical Advantage.
Is there a big difference as between the theoretical and actual
values? Is the bicycle an efficient machine?
Note: If a 15 kgm. spring balance is not available the pro-
cedure may be reversed by tieing a large weight, say 10 kgm. or
10 lb., to the pedal and attaching a small spring balance to the
tire and pulling downwards to support the weight on the pedal.
In this case, however, the weight of the spring balance must be
added to its reading to determine the true value of the resistance.
The Inclined Plane
Object: To determine the Mechanical Advantage of the In-
clined Plane and to calculate the efficiency of this machine.
Reference: ''Modern Physics," Sections 216 and 217- Also re-
view Sections 203 and 204.
Apparatus: The Inclined Plane apparatus and car, weights,
spring balance, metre stick, string. If the regular inclined plane
apparatus as supplied by scientific manufacturing companies is
not available, a smooth board 6 in. wide and five feet long and a
model car made from a Meccano set with its bearings well lubri-
cated may be used.
Procedure: Set up the inclined plane at an angle of about 30°.
Weight the car on the spring balance and attach a long string to
the hook. Place it on the plane with a 500 gm. weight in it.
Attach the string to the balance, pass the string over the pulley
at the top of the plane and, applying a horizontal pull, determine
the force required to pull the car up the slope. This force repre-
sents the effort required to overcome the pull of gravity and the
Take a second reading as the car runs slowly down the plane.
This represents the effort less the amount due to friction. The
average of these two values gives the true force needed to over-
come the pull of gravity down the plane.
Measure a distance of 100 cm. along the lower edge of the
inclined plane from the point where it contacts the table, and
mark the distance on the edge of the plane. Measure the vertical
height of the plane at this point from the table.
Results: Repeat the experiment twice changing the angle of
the plane for each trial.
Tabulate all data as follows :
Efficiency =^^X 100
Note: In the formula for efficiency given above E is the effort
required to pull the car up the slope; i.e-, EffortH- Friction since,
in this machine, useful work is only done w^hen the weight is
moved up the slope.
What is the theoretical Mechanical Advantage of the Inclined
Plane ? What is the actual M. A. ? What is the relation between
the Mechanical Advantage and the angle of the slope?
Determination of Specific Heat
Object: To determine the specific heat of aluminum or other
suitable metal by the method of mixtures.
Reference: "Modern Physics," Sections 269-272, with par-
ticular reference to Section 271.
Apparatus: Insulated calorimeter, thermometer, boiler or
florence flask, burner, balance, set of weights, length of string,
metal block or shot.
Note: In this experiment the best results are obtained using
a block of aluminum, since aluminum has a high specific heat.
The usual method of heating some lead shot in a test tube sup-
ported in the neck of a florence flask containing boiling water
may, however, be used. Care must be taken in this case to see
that the lead shot is uniformly heated and that the thermometer
inserted in the shot measures the average temperature of the
shot. In reading the thermometer always estimate fractions of
a degree to the nearest tenth. A small error in the thermometer
reading can result in a large error in the specific heat.
Method : Tie a piece of string to the metal block and weigh it.
Or, if lead shot is to be used weigh out about 200 gm. of shot and
transfer to a test tube. (A piece of heavy insulated wire twisted
around the test tube serves both as a handle and as a means of
supporting the test tube in the neck of the florence flask for
Put the aluminum in a boiler half full of water with the
string hanging outside. Heat the boiler with a bunsen or other
burner. Weigh the calorimeter (the inside vessel only, if it is a
double insulated calorimeter). Fill the calorimeter 2/3 full of
water and weigh it again. The water used should be several
degrees below room temperature. Take the temperature of the
steam in the boiler. Stir the water in the calorimeter gently
with the thermometer and record its temperature.
Now raise the aluminum block so that it hangs only in the
steam of the boiling water for a minute or so. Record the tem-
perature of the metal as that of the steam in which it is suspended.
Place the calorimeter in an insulating vessel supporting it in a
fibre ring or cotton wool packing. Quickly transfer the aluminum
block which should be quite dry to the calorimeter and take the
resulting temperature, moving the block up and down to ensure
thorough mixing of the water. If lead shot is used it may be
quickly dumped into the water and stirred with the thermometer.
Results: Tabulate all readings and weights and calculate the
specific heat of the metal in the manner illustrated in Section 271
of the textbook.
Compare your result for the specific heat of the metal with
the value given in Table 6, Appendix B, "Modern Physics."
^ ^ 1 J. J.1 4. J.U Actual error ^ ^ ^^
Calculate th^ percentage error thus : ^ —r — p X 100.
In your conclusion to the experiment indicate the most prob-
able sources of error.
Heat of Fusion of Ice
Object: To determine how many calories of heat are required
to melt one gram of ice at its melting point.
Reference: "Modern Physics," Sections 277-279. Study the
method of solving the problem on heat of fusion in Section 278.
Apparatus: Insulated calorimeter, balance, weights, thermo-
meter, ice, towel. The thermometer should be graduated in Centi-
grade degrees and should be read carefully to the nearest tenth
of a degree.
Procedure: Weigh the calorimeter — inside vessel only; fill it
with about 250cc. of water at 40° C ; weigh again. The difference
in the two weighings will give the weight of water taken. Break
up the ice into pieces about one inch across. Take the tempera-
ture of the water in the calorimeter as accurately as possible
having first placed the calorimeter in the insulating vessel. Re-
move excess moisture from the ice by wiping it with a cloth and
introduce it into the calorimeter taking care not to lose any of the
water by splashing. Stir the water constantly and take the
temperature, adding more ice from time to time until the tem-
perature is around 5°C. Stir until the ice is all melted and take
the final temperature accurately.
Now weigh the calorimeter to determine the weight of ice
which has been added.
Results: Following the method illustrated in Section 278 of
the textbook, calculate the heat of fusion of ice in calories per
gram. Tabulate all weights and temperatures neatly and show
all calculations.^ Determine the percentage error in your result.
Indicate the chief sources of error which you think may have
arisen in your experiment. If these include errors of manipula-
tion, repeat the experiment and try to get a more accurate result.
Object: To determine the boiling point of certain liquids and
to illustrate the process of fractional distillation.
Reference: "Modern Physics," Sections 288-290. Study care-
fully the correct method of setting up a condenser as illustrated
in Fig. 334, page 242 of the textbook.
Apparatus: A Liebig's condenser, distilling flask, 25 cc gradu-
ate, thermometer, receiving flask, alcohol, 10% solution of salt
Note: Wood alcohol, used for spirit lamps, is methyl alcohol,
B.P. 66°C. Commercial grain alcohol is 95% ethyl alcohol, B.P.
78 °C. Rubbing alcohol is chiefly ethyl with an admixture of
methyl and other ingredients to ''denature" it.
Procedure: Set up the apparatus as shown in Fig. 334, p. 242
of the textbook.
(a) Pour 100 cc. of tap water into the distilling flask and
heat it to boiling. Have the bulb of the thermometer one inch
from the surface of the water. When the thermometer remains
steady take the temperature. If a mercury barometer is avail-
able take the atmospheric pressure in millimetres of mercury.
Record these readings. Boil the water for two or three minutes
and again record the boiling temperature.
(b) Replace the water in the distilling flask by 100 cc. of
alcohol and determine its boiling point. Use a clean receiver for
Pour the alcohol that has distilled over back into the flask
and add 100 cc. of water. Determine the boiling point of the mix-
ture. Continue to boil the mixture until 25 cc. has distilled over.
Again record the boiling temperature.
Repeat with each of three more portions of 25 cc- of distillate,
taking the temperature after each. Save the alcohol for future
(c) Throw away the liquid left in the distilling flask, wash
out flask and pour in 100 cc. of 10% salt solution. Determine the
boiling point at intervals of three minutes as long as time permits.
Results: (a) What is the boiling point of water? Does the
B.P. rise with continued boiling? Refer to Table 9, Appendix B
of the textbook. At what temperature should water boil at the
recorded atmospheric pressure? How does this check with your
recorded B.P. ?
(b) What is the boiling point of pure alcohol? Is it ethyl or
methyl alcohol ? What is the boiling point of a mixture of alcohol
and water? How does the boiling point change for the successive
distillate fractions? How may this be explained?
(c) Tabulate the data from experiment (c). Account for
any change in the boiling point of the salt solution.
Heat of Vaporization of Water
Object: To determine the number of heat units required to
change one gram of water into steam at its boiling point.
Reference: "Modern Physics," Sections 291-293. Study the
method of determining the heat of vaporization of water as
worked out in Section 292.
Apparatus: Steam boiler, water trap, rubber tubing, glass
tube, balance, weights, insulated calorimeter, Centrigrade ther-
Note: If a copper boiler is not available, fit up a florence flask
half full of water, having a bent delivery tube passing through a
one-holed rubber stopper. Heat it over wire gauze on a tripod.
Procedure: Attach the water trap to the outlet pipe of the
boiler or florence flask by means of rubber tubing. While the
water is heating weigh the inside calorimeter vessel; fill it two-
thirds full of water at about 5°C. (Snow or ice may be added to
reduce the temperature of the tap water if necessary.) Weigh
again to determine the weight of cold water in the calorimeter.
Attach the glass tube to the lower end of the water trap by
means of rubber tubing. Take the temperature of the water in
the calorimeter reading accurately to tenths of a degree. Place
the glass tube below the surface of water in the insulated calori-
meter (Fig. 337, textbook), and pass a steady stream of steam
into the calorimeter until the temperature has risen to about
40 °C. Remove the delivery tube, stir the water in the calori-
meter to determine its temperature. Now weigh the calorimeter
to determine what weight of steam has condensed in the water.
Take the temperature of the steam while the water is still
boiling in the boiler.
Results: Following the procedure illustrated in the textbook
(Section 292), tabulate all data and calculate the heat of vapori-
zation of water.
Compare your result with that given in table 6, Appendix B,
of the textbook, and estimate the percentage error. Indicate the
most probable sources of error in this method.
Dew Point and Relative Humidity
Object: To determine the dew point and the relative humidity
of the air in the room.
Reference: "Modern Physics," Sections 300-306. See also
"Elements of Physics,'' by Merchant and Chant, Sections 242-248,
for a description of Regnault's dew-point hygrometer and the
method of determining the relative humidity from the dew point.
Apparatus: Either a Regnault's polished cup hygrometer or a
highly polished metal cup, ether, ice, thermometer (Fahrenheit) ;
either a hygrodeik or a wet-bulb thermometer prepared by tieing
a fresh spirit lamp wick around the bulb of a Fehrenheit ther-
mometer, the lower end of the wick dipping into distilled water.
Note: If only Centigrade thermometers are available, refer to
the table on p. 258, "Elements of Physics,'' by Merchant and
Chant, for working out the relative humidity from the dew point.
Procedure: (a) Using Regnault's hygrometer. Po.ur into the
polished cup about 5cc. of ether. Adjust the thermometer, bent
delivery tube and straTght exit tube in the cork so that the bent
delivery tube is below the surface of the ether but the outlet tube
and thermometer bulb is above the ether. Attach an atomizer
bulb to the bent delivery tube and gently force air through the
ether so as to cause it to evaporate rapidly. Observe the drop in
the thermometer and without breathing on the polished cup note
the moment that a faint film of moisture appears on its surf ace.-'
Immediately read the thermometer and record reading. Stop
blowing air through the ether and watch the film of moisture on
the polished cup. Record the temperature at which the film dis-
appears. The average of these is the dew point. Repeat the ex-
periment twice more and take the average value of the dew point.
(b) A polished cup or tin can. may be used as follows: Fill
the cup one-third full of water at room temperature. Add ice and
stir with a thermometer until a film of moisture appears on the
metal cup. Record the temperature at which the film appears and
when it disappears. The average is the dew point. Repeat the
experiment twice, using a fresh supply of water and ice.
Note: It may be necessary to add warm water to make the
film disappear from the metal surface.
In either method (a) or (b) record the room temperature.
Using a hygrodeik or wet-and-dry bulb hygrometer, determine
the relative humidity by reading the two thermometers. The wet
bulb should be gently fanned with a piece of stiff paper to obtain
an accurate reading. Record the two readings.
Results: (a) Having determined the dew point in Fahrenheit
degrees, refer to Table 5, Appendix B, "Modern Physics,*' and de-
termine the moisture capacity in grains per cubic foot at the dew
point and also at the temperature of the room. The relative hu-
midity may then be determined by the following formula :
T^ 1 ,. TT -j-i™ Water Vapour capacity at dew point .^^^^
Relative Humidity= ^t^t-t — ^rr^ .. , r^ XIOO.
Water Vapour capacity at room temp.
If a Centigrade thermometer has been used, the temperature
may be converted into Fahrenheit readings, or the table referred
to above in ''Elements of Physics," by Merchant and Chant, may
From the wet-and-dry bulb thermometer readings determine
the relative humidity by reference to Table 16, Appendix B, of
Compare your results for the relative humidity of the room
by the two methods. If there is not a fairly close agreement
(within 5%) by the two methods, indicate in your conclusion
which method you consider to be the most accurate.
Lines of Magnetic Force
Object: To map the lines of force about magnets.
Reference: "Modern Physics," Sections 510-513. Look up.
in an encyclopedia or chemistry textbook, the method of prepar-
ing blue print paper. This makes a good chemistry project. The
paper may be bought at little expense from a supply house.
Apparatus: Two bar magnets, horseshoe magnet with arma-
ture, iron filings, sieve or perforated metal box, pan, pins, blue
print paper, board 1 ft. square with grooves cut parallel to hold
bar magnets and of the same depth as the thickness of the
Procedure: Place a bar magnet in the grooved board in a part
of the room where the light is subdued. Pin a sheet of blue print
paper (9 x 11 in.) with the sensitive side up on the board so that
the bar magnet is below the centre of the paper. Sprinkle iron
filings in a thin layer evenly over the surface of the paper. Tap
gently with the fingers until the filings arrange themselves in the
direction of the lines of force. Without disturbing the arrange-
ment of the iron filings, hold the board so that the paper is ex-
posed to direct sunlight for about five minutes- At the end of this
time the paper should have acquired a brownish colour. Remove
the pins, shake off the filings into a pan, and develop the print by
washing it in water until all the yellow colour has disappeared.
Spread the blue print on a pane of glass to dry, face down.
Repeat the experiment with two bar magnets placed with
like poles adjacent, with unlike poles adjacent, and with a horse-
Results: When the blue prints are dry, label each, trim them
to a suitable size and preserve them in your notebook. Compare
the results with the diagrams shown in your textbook. Are there
any irregularities in the lines of force shown on your blue prints ?
Comment on the possible cause of these.
Note: If time does not permit each group to do all of these,
they may be divided up among the groups and the results put on
display for the whole class to study. Other arrangements, such
as two magnets placed at right angles in the form of a cross, or
three bar magnets forming a triangle, or a magnet with a soft
iron ring to illustrate shielding may be tried.
The Voltaic Cell
Object: To set up a simple voltaic cell and to study its action.
Reference: "Modern Physics," Sections 545-550.
Apparatus: A simple demonstration cell, consisting of a glass
jar with removable clamps to support the elements, two zinc
strips, copper strip, carbon rod, D.C- voltmeter (1-15 volts or
lower) Daniell cell, amalgamating fluid. No. 18 insulated copper
Note: The amalgamating fluid may be prepared in the chem-
istry lab. by dissolving 5 cc. of mercury in aqua regia (60 cc. of
nitric acid mixed with 200 cc. of hydrochloric acid) .
Procedure: Prepare some diluted sulphuric acid, 1 part acid to
20 parts water; fill the glass jar one-third full with the acid and
place a strip of zinc in it. What gas is given off? Complete the
Note the colour of the zinc after a minute or two. What im-
purity in the zinc causes this appearance? (See Section 549,
textbook.) What is meant by local action and how is it related
to this impurity?
Dip one end of the zinc strip (2 or 3 in. of it) in the amalga-
mating fluid. Leave it for one minute, then remove, rinse and
wipe dry. Describe its appearance.
Now put the amalgamated zinc strip in the sulfuric acid.
How does its behavior compare with the previous action of the
zinc strip? Explain the advantage of coating the zinc with
Remove the zinc strip from the acid, wash it and place it in
a beaker or in the sink. Avoid spilling or splashing the acid ; it is
Place a copper strip in the acid. Is there any action? Re-
peat using a carbon strip. Any action?
While the carbon is still in the acid, place the amalgamated
zinc strip also in the acid but not touching the carbon. Is there
any action visible when the cell is on open circuit? Attach the
carbon and zinc strips to the terminals of the demonstration cell
and attach the terminals to the voltmeter using the copper wire.
Observe the action of the cell and note the strip from which hy-
drogen gas rises. Record this. Record also the reading of the
voltmeter. This is the E.M.F. of the cell.
Short-circuit the cell by joining the two terminals by a short
length of heavy copper wire. Leave it for a few minutes, then
remove the shunt wire and again read the voltmeter. Record
this. What is the appearance of the carbon strip now? What is
the name for this effect?
Now lift the strips from the solution, wipe off the bubbles of
gas and replace in the solution. Read the voltmeter and record.
Does the voltage return to its original value ? Again short-circuit
the cell with the shunt wire until it is polarized. Add a few cry-
stals of sodium or potassium dichromate to the sulfuric acid and
stir. What is the effect of the dichromate crystals on the read-
ing of the voltmeter? What kind of an agent is potassium or
sodium dichromate? What is the effect on hydrogen? What is
the essential property of a good depolarizer?
If time permits, set up the Daniell cell as follows : In the por-
ous jar pour dilute sulfuric acid (1 of acid to 20 of water) . Place
an amalgamated zinc strip in the acid. Place the porous jar in
the glass battery jar and fill the latter with a saturated solution of
copper sulfate to the same depth as the acid in the porous jar.
Insert the copper plate in the solution of copper sulfate- Allow
time for the liquid to soak through the porous vessel and deter-
mine the E.M.F. of the cell with a voltmeter. Record the reading.
Short-circuit the cell with the copper wire as before for two min-
utes and again record the voltage. Does this cell polarize?
Remove the copper plate and examine it. Is there a deposit
on its surface? What is it? The action at the positive plate is
represented by this equation : ;
H2 + CuS04=H2S04+Cu.
If the Daniell cell is to be left standing for future use con-
nect it in series with a 40 ohm resistance.
Results: Tabulate all observations and readings and summar-
ize your conclusions as to the cause and remedy for (a) Local
action, (b) Polarization in the voltaic cell.
Draw a diagram of the Daniell cell and explain its operation.
Grouping of Cells
Object: To study the different ways in which cells may be
grouped and to determine the advantage of one method over
Reference: "Modern Physics/* Sections 555-559. Study the
rules which apply to (a) cells in series, and (b) cells in parallel
as listed in Section 558.
Apparatus: Three Daniell cells, voltmeter, ammeter, resist-
ance coils. No. 18 insulated copper wire.
Note: A gravity cell is a form of Daniell cell that may be
used for this experiment. The simple voltai<: cell is not suitable
owing to polarization. Three dry cells may be used but since their
internal resistance is very low, it may not be easy to show the
advantage of parallel connections for certain resistances with
Procedure: Connect a Daniell cell to the voltmeter by means
of No. 18 copper wire and determine the E.M.F. Disconnect the
voltmeter and connect in an ammeter and determine the amper-
age without other external resistance. Record the voltage and
amperage. Connect the cell to a resistance of about 5-30 ohms
and determine the amperage.
Connect three Daniell cells in series (Fig. 607, textbook) and
test the combined E.M.F. with a voltmeter connected across the
outside terminals of the series group. Record the voltage.
Now connect the three cells in series with the ammeter and
a 40 ohms resistance. Record the amperage. Note that the
external resistance of 40 ohms is large compared with the com-
bined internal resistance of the cells.
Now connect the three cells in series directly to the ammeter.
Record the amperage. In this case the external resistance, that
of the ammeter and connecting wires, is quite low, less than the
internal resistance of the cells.
Repeat the procedure using the three cells in parallel (Fig.
609, textbook). Record the voltage and amperage alone, and
when the parallel group of cells is connected with the 40 ohm
resistance in series with the ammeter.
Results: Tabulate the data as follows
40 ohms R.
From the tabulated results indicate which method of group-
ing gives the maximum current: (a) when the external resist-
ance is large compared to the internal resistance, (b) when the
external resistance is smaller than the internal resistance.
Object: To determine the resistance of an unknown resistor
by the application of Ohm's law.
Reference: "Modern Physics," Section 553 and the first part
of Section 619. For a more detailed explanation of Ohm's law as
used for the determination of the resistance of a conductor, read
"Elements of Physics," Sections 535-536. Note Fig. 610 in "Ele-
ments of Physics" for the method of connecting the apparatus
for this experiment.
Apparatus: Ammeter, voltmeter (these should be graduated
in tenths) , rheostat or resistance box, battery of 5 or 6 volts, No.
18 wire for connections, or Pietenpol connectors, a length of re-
sistance wire of unknown resistance as supplied by your teacher.
This may be of any value between one ohm and 30 ohms.
Procedure: Connect in series the following: Battery, knife
switch, rheostat or variable resistance box, unknown resistor,
ammeter. Across the ends of the unknown resistor connect in
parallel the voltmeter. Set the rheostat so as to include only a
few turns of wire, or, if a resistance box is used, set it at one ohm.
Close the knife switch and immediately take the readings of
both voltmeter and ammeter, reading to the nearest hundredth of
an ampere or volt. Note: If the instruments are graduated in
tenths, this will involve estimating the fractions of a division by
judging with the eye the approximate fraction and expressing it
as tenths. This will give the second decimal point in your read-
ing. The knife switch should not be left closed for more than a half
minute at a time, as the resistors will heat up and the resistance
change while you are reading the instruments. Record the read-
ings in a table as shown below. With the knife switch open,
change the position of the rheostat or set the variable resistance
at 2 ohms and, closing the switch, again take readings of the am-
meter and voltmeter. Repeat the experiment with a gradual in-
crease in the resistance of the variable resistance taking readings
of the ammeter and voltmeter each time. Obtain five sets of
Results: Tabulate all data as follows:
Resistance Tj_ E
in ohms I
Is the value for R, i.e., the unknown resistance, constant?
Take the average value of the ^ve trials. If the material of
the unknown resistance wire is known, measure its length and
diameter (micrometer screw gauge) expressed in feet and mils
and, applying the formula on p. 442 of ''Modern Physics,*' calcu-
late the resistance in ohms. Compare this value with the method
of your experiment. Which do you consider the more accurate?
The Wheatstone Bridge
Object: To determine the resistance of a conductor by the
method of Wheatstone's Bridge.
Reference: ''Modern Physics," Section 619. Study Fig. 683,
p. 492, for the method of connecting the apparatus.
Apparatus: A slide-wire Wheatstone bridge, dry cell, D'Ar-
sonval type of galvanometer, resistance box, an s.p.s.t. knife
switch, connectors and an unknown resistance to be determined.
Procedure: Connect up the apparatus in the manner illus-
trated in Fig. 683 of the textbook. Use short lengths of No. 18
wire for the connectors. Place the resistor to be determined at
X; connect in the adjustable resistance box at R. Connect the
galvanometer across the points DK, using a short wire at D but
a piece about 50 cm. long from the galvanometer to K. Connect
the dry cell across the ends of the German silver wire AC, insert-
ing a single-pole-single-throw switch between the battery and
Note: This is not shown in Fig. 683, but it is advisable so that
the battery circuit can be opened when readings are not being
taken, thus avoiding wastage and overheating of the resistance
Slide the contact key to the 50 cm. mark and remove the 100-
ohm plug from the resistance box. This introduces a resistance
of 100 ohms at R. Now press down the key K and observe the
needle of the galvanometer. Note: Make sure the galvanometer
needle is able to turn freely and that the coil to which it is at-
tached does not touch at any point as it swings. The reading
should be zero when no current is passing through the galvano-
meter. The needle will probably jump violently when the key K
is depressed. Adjust the resistances in the box R, either more or
less until the motion of the needle is no longer violent and it
moves over a few degrees of the scale.
Note: The plugs in the resistance box should be pressed in
firmly to make good contact each time they are replaced.
To make the final adjustment so that the bridge is "bal-
anced" and the galvanometer registers zero deflection, move the
sliding key K to right or left as may be required until, on depress-
ing the key, the galvanometer registers zero.
Read the value of the resistances in the resistance box and
the exact ix)sition of the key K to the nearest millimetre at the
point where it touches the wire. Record these.
Results: Tabulate the data and, using the method explained
on p. 492 of the textbook, work out the value of the unknown re-
sistor X in ohms.
Knowing the dimensions of the resistor, i.e., its length in
feet and its diameter in mils, determine the value of K in the
formula for resistance.
Compare this value with the accepted value for the material
of the resistor as given in Table 15, Appendix B, of the textbook.
Repeat the experiment using the dry cell, only in this case
connect a low resistance shunt across the terminals of the am-
meter. Remember your ammeter is a valuable instrument. Pro-
tect it from an overload.
Results: Tabulate all results as follows:
Compare the results as given by the two methods. Which is
more accurate? Give reasons.
Internal Resistance of Cell»
Object: To determine the internal resistance of a cell (a) by
Ohm's law method, (b) by the reduced deflection method.
Reference: "Modern Physics," Section 556.
Apparatus: A Daniell or gravity cell, voltmeter and am-
meter, both graduated in tenths, knife-switch, resistance box, dry
Procedure: Connect the gravity of Daniell cell in series with
a switch, ammeter and resistance box. Connect a voltmeter
across the terminals of the cell. See Fig. 605, p. 442 of textbook.
With the switch open read the voltmeter. Record this read-
ing as E volts.
Since this cell has a high internal resistance, it is not neces-
sary to put any other resistance in the external circuit. The re-
sistance box may therefore be set at zero and the switch closed.
Read the voltmeter and ammeter. Record the ammeter reading
(I), and the voltmeter reading (E ).
Calculate the resistance of the cell by applying Ohm's law as
^ — r-
Repeat the experiment with the dry cell in place of the-
Daniell cell. In this case a small resistance must be introduced
in the resistance box before closing the switch.
Note: The current from a dry cell is too heavy to be put
through the ammeter without some resistance in the circuit. Do
not bum out your ammeter. Have your teacher check your ap-
paratus before proceeding.
(b) Reduced deflection method. Connect the Daniell cell,
switch, ammeter and the resistance box in series. With a zero
resistance in the resistance box, close the switch and take the
ammeter reading. Record this. Now remove plugs from the
resistance box until enough resistance has been introduced to re-
duce the ammeter reading to exactly one-half. Record the re-
sistance of the resistance box. This is a measure of the internal
resistance of the cell.
Magnetic Field about a Conductor
Object: To perform Oersted's experiment and to study the
nature of the magnetic field about a wire carrying a current.
Reference: ''Modern Physics," Sections 561-564.
Apparatus: A galvanoscope having one turn, several turns
and many turns, each with their respective binding posts, Pieten-
pol connectors, 2 dry cells or storage battery, Daniell cell, knife
switch, four small compasses, one large demonstration compass
needle, sheet of stiff cardboard 1 ft. square, length of bare No. 12
or No. 14 copper wire.
Procedure: (a) Test Oersted's experiment as illustrated in
Fig. 611 and Fig. 612, using the Daniell cell and a demonstration
compass needle. Test the right-hand rule for determining the
direction of the current. Place the wire above and below the
needle and reverse the connections on the Daniell cell, testing the
rule each time.
(b) Place the galvanoscope on the bench so that the single
wire is parallel to the compass needle as it points towards the
magnetic North pole. Turn the compass so as to bring the zero
point directly below the North pole. Connect the Daniell cell with
the knife switch in series with the terminals of the single gal-
vanoscope wire so that when the switch is closed the current will
flow from South to North over the needle.
Close the switch and note the direction in which the North
pole is deflected and the number of degrees on the compass scale.
Reverse the connections of the Daniell cell so that the current
flows from North to South. Close the switch and read the number
of degrees of the angle of deflection. Record these readings. With-
out changing the position of the galvanoscope on the bench,
repeat the experiment with the compass needle under the few
turns of wire. Record the angle of deflection for both directions
of the current flow.
Repeat again with the many turns of wire. Record the
angle of deflection of the needle.
(c) Pass the heavy copper wire through a hole in the sheet
of cardboard, supporting the latter in a horizontal position by
means of a wooden clamp. Note: An iron retort stand is fre-
quently magnetized and may give erroneous results.
Connect the ends of the copper wire to two dry cells or a
storage battery and the knife switch in series using No. 18 wire.
Place the four small compass needles around the wire in the man-
ner illustrated in Fig. 613 of the textbook.
Close the switch and observe the position of the compass
needles. Reverse the connections so that the current flows in the
opposite direction, close the switch and again observe the position
of the needles. Apply right-hand rule No. 2 on p. 452 for both
Results: Tabulate the results of experiment (b) and state the
effect of increasing the number of turns of wire.
Draw diagrams to illustrate the positions of the compass
needles in experiment (c) : (i) when there is no current, (ii)
when the current flows upward, (iii) when the current flows
Efficiency of Lamps
Object: To determine the efficiency of various lamps and to
compare series and parallel wiring for lamps.
Reference: "Modern Physics," Sections 599 and 600.
Apparatus: A.C. voltmeter, 0-150; A.C. ammeter, 0-10; 3 40-
watt lamps, 1 25-watt, 1 60-watt, 1 100-watt lamps ; 16-c.p. and
32-c.p. lamps ; a lamp board to be constructed as follows : On a
piece of 3-ply wood, 6" x 3', set out three lamp sockets about 8"
apart and towards one end of the board. Screw them to the
board and connect them, in parallel (Fig. 654), with a heavy in-
sulated electrician's wire. Remove only enough of the insulation
to make good contact on the sockets. Spread the rest of the wire
along the board and fasten the ends to two terminal binding
posts, well insulated, at the extreme end of the board. On one
wire insert a lamp socket to take a fuse plug and a single-pole-
single-throw porcelain based knife switch. Cut the wire at two
points equally spaced between the terminal post and the first
lamp socket, and insert the fuse socket and the knife switch in
series with each other. On the other wire insert another lamp
socket to take a second fuse plug and two binding posts for at-
taching an ammeter. You should now have in series going from
one binding post to the other, a lamp socket (A) , a knife switch,
a group of three lamps (B, C and D) in parallel, two binding
posts (M and N), and another lamp socket (E).
Procedure: (a) Connect the terminals of the lamp board to
an A.C. 110- volt outlet by means of a lamp cord and plug. Insert
two 6-ampere fuse plugs in sockets A and E. These are to pro-
tect the measuring instruments.
Place a 25-watt lamp in socket B. Connect an ammeter
across M and N and a voltmeter across the terminals of the lamp
B. Close the switch and read the ammeter and voltmeter. Re-
cord the readings in a table as shown below.
Do the same for the 40-watt, the 60-watt, the 100-watt, the
16-c.p. carbon and the 32-c.p. carbon lamps.
Record all readings. Note: Open the knife switch each time
you replace a lamp in socket B.
(b) Place a 40-watt lamp in B. Take readings and record.
Place another 40-watt lamp of the same make in C.
Close the switch and read the ammeter and voltmeter.
Open the switch and transfer the voltmeter to the terminals
of lamp C. Record readings.
Insert a third identical 40-watt lamp in socket D. Close the
switch and read the ammeter and voltmeter, changing the latter
to D after checking to see if there is any change in the reading at
C. Record all readings.
(c) Remove the fuse plug nearest to the ammeter and insert
a 40-watt lamp in its socket (E) . Remove lamps from C and D.
You now have lamps in B and E in series. Close the switch and
determine the ammeter reading and the voltage across each lamp
separately and across the two together. Record all readings.
Results: Tabulate the data of experiment (a) as follows, tak-
ing a 25-watt lamp to have a 20 c.p., a 40-watt lamp to have a 32
c.p., a 60-watt lamp to have a 50 c.p., and a 100-watt lamp to
have 100 c.p. :
Cost of electricity to be reckoned at 10c per kilowatt-hour.
Tabulate the results of experiments (b) and (c) thus:
No. of lamps
What are the advantages of parallel wiring for lamps over
Object: To study induced currents.
Reference: ''Modern Physics,'' Sections 620-623 and 642.
Apparatus: Primary and secondary coils with core, or Gilley's
induction study outfit, or home-made coils as in figure 718 of
text ; bar magnet small enough to enter larger coil, sensitive gal-
vanometer, dry cell.
Procedure: (a) Connect the larger coil to the galvanometer.
Hold the magnet about six inches away from the coil with the
north pole nearer to it. Thrust the magnet quickly into the coil,
hold it there a moment, pull it out. Note the direction of any
deflection of the galvanometer needle. Work out the direction
of flow of the currents in the coil. Work out the polarity of the
end of the coil nearer the magnet for each current.
Repeat using the South pole of the magnet.
Record your results as follows :
Direction of current in
coil. (Clockwise or
counter clockwise in
face nearer the magnet)
(b) Connect a dry cell to the smaller coil. Use this coil in
the same manner as you did the magnet in (a) , pushing it in and
out of the larger coil. Note the movements of the galvanometer
Repeat with the core in the smaller coil.
Repeat with the current reversed.
Record in a manner similar to that used in (a) , showing in
the last column whether the induced current is in the same or the
opposite direction to the current in the primary.
What was the effect of putting the core in the smaller coil?
Does the induced current always oppose the primary
(c) Disconnect one wire from the cell. Place the smaller
coil inside the larger. Touch the disconnected wire to its binding
post ; remove it after holding it there a moment. Note any move-
ment of the galvanometer needle while the circuit is being closed
and opened. Repeat with the core in the smaller coil.
Record your results as in (a) and (b).
Does any current flow in the secondary while a current flows
steadily in the primary?
Which induces the larger current, making or breaking a
What is the effect of the core?
Does the induced current always oppose the change which
The Electric Motor
Object: To study the action of a simple electric motor.
Reference: "Modern Physics," Sections 635-640.
Apparatus: St. Louis type demonstration motor, dry cell.
Procedure: Remove the bar magnets from their holders and
connect the dry cell to the armature terminals. Turn the arma-
ture by hand through a complete circle and test the polarity of
each end of the armature by means of a bar magnet (law of mag-
netic poles) at several points in the circle. Note the change in
polarity as the two segments of the commutator move from one
brush to the other. Draw diagrams as in Figs. 708-710, p. 508
of textbook, and indicate the polarity in different positions.
Now insert the bar magnets so that a North pole of one and a
South pole of the other are close to the armature. Connect the dry
cell as before and set the armature rotating.
Study the effect of separating the magnets further apart on
the speed of the motor, and the effect of using two like poles. Re-
verse the connections of the dry cell. Note the direction of rota-
tion of the motor. Now disconnect the dry cell, remove the bar
magnets and insert the electro magnet. Connect the dry cell, the
armature terminals and the field magnet all in series. Note the
direction of rotation of the armature. Change the connections on
the dry cell so as to reverse the direction of the current. Note the
direction of rotation now. Is there any change? Why is this
different from the effect with permanent field magnets?
Now connect the armature, the field magnet and the dry cell
in parallel. Again try the effect of changing the connections on
the dry cell so as to reverse the direction of the current. How
does this affect the direction of rotation of the motor?
Results: Draw diagrams to show the connections, the direc-
tion of current flow and direction of rotation, also polarity of the
field magnets for each of the three types used, i.e., (i) using per-
manent field magnets, (ii) series wound motor, (iii) shunt
DIRECTIONS TO STUDENTS
1. Before coming into the laboratory to perform an experiment,
study the directions outlined here in the procedure. Be sure
that you understand what you will be doing, and why. Do not
attempt an experiment the relevant theory, of which you have
not already studied.
2. Question each step as you proceed. Learn the names of the
chemicals and apparatus. Examine materials used ; and also
the precipitates formed, and other products, so as to be able to
identify them as your work progresses.
3. Follow the directions closely and use great care when flames,
acids, and bases, and inflammable liquids are employed.
4. Use small quantities of chemicals. Larger quantities fre-
quently retard the progress of the experiment.
5. Record all results of your experiment and make liberal use of
diagrams (sectional) in making your report. These diagrams
should be neatly drawn and neatly labelled.
6. Be sure your apparatus is clean. After completion of the ex-
periment, clean all apparatus and leave the desk in a dry and
7. Learn the capacity (in cc.) of an ordinary test tube so as to
be able to measure out approximate volumes (10 cc.) without
loss of time.
8. In case of accident, call your instructor at once.
In the following exercises —
^'Result?" means to make a written record of your obser-
Interpret "Odour?" ^'Equation?" also in written form.
Unless the word "dilute" is used before an acid, the concen-
trated acid is to be used.
Bracketed numbers refer to related material in the author-
LIST OF EQUIPMENT: CHEMISTRY 2
This list makes adequate provision for practical work. At
the present time, however, it may be difficult to get some of the
apparatus and materials listed ; and it may be necessary for in-
structors to improvise equipment and substitute other materials.
SUPPLIES FOR SIX STUDENTS
The following is a list of the supplies needed for six students
working in three groups of two each or for three students work-
ing singly. A reasonable margin has been allowed for break-
ages. It includes several pieces of equipment which are also re-
quired for Chemistry 1. The list is divided under sub-headings
as follows :
A. — Apparatus required for all groups. It is desirable that
this be issued at the beginning of the year, especially if
drawers and cupboards lock.
B. — (1) Apparatus for common use of several groups. This
should be considered a minimum list.
(2) Additional and more extensive apparatus which
should be included for large classes or even for
small ones if circumstances permit.
C. — Chemicals.
D. — Materials which may be obtained locally.
A. — ^Apparatus required for all groups.
(Quantities are sufficient for three groups.)
Note: "Pyrex" or some good resistance glass is recommneded for
all glassware. Although it is more expensive, it is so much more
durable that its use results in greater economy being effected.
Alcohol lamps, 4 oz. at least (or bunsen burners with
the fish tail attachments if gas is available) 3
Beakers, low form with lip, 250 cc 6
Beakers, low form with lip, 150 cc 6
Blowpipes, 8-10 inches, brass recommended 3
Blue Glasses, 2" x 1" 3
Bottles for collection of gases, etc., at least 8 oz., low
Bottles for reagents, glass stoppers, at least 4 oz 30
Burettes, 50 cc, Mohr type for pinchcock recommended 3
Burette, fittings for above, burette tip with rubber tub-
ing and pinchcock 3
Filter papers, 5" in dia., coarse for rapid work 1 pkg.
Flasks, Erlenmeyer, 300 cc. No. 6 top 4
Rubber stoppers, two holes, No. 6 for the above flasks 4
Funnels, glass, 65 mm. dia., 150 mm. stem 3
Glass tubing, 6 mm., ext. dia 1/8 lb.
Graduates, 100 cc to show 1 cc. 3
Graduates, 10 cc. 3
Non-combustible rods for flame tests (or see B list) .... 3
Pipettes, 10 cc, (Note: 3 burettes may be used in-
Pneumatic troughs, galvanized iron or glass, about
Retorts, 125 to 250 cc, glass for making bromine 3
Retort stands, base, about 31/2" x 6I/2" ' 3
Retort stands, rings— large 3%" dia. inside; small,
21/2" dia 3 each
Retort stands, fixtures, burette clamp 3
Rubber tubing, 3/16" dia. inside for generators and
connections 8 ft.
Test Tubes, 16 mm. dia. outside, 150 mm. long 30
Test Tubes, 20 mm. dia. outside, 150 mm. long (prep.
of O2) 5
Rubber stoppers, 1 hole, size No. 2, large end, 20 mm. 3
Test Tube brush, bristle end 3
Test Tube racks, large enough to hold 10 tubes upright
Thistle tube, stem, 6 mm. dia. outside 4
Tubes, combustion, dia. inside, about 15 mm., length
Wire gauze squares, iron or copper, 4" side 3
B. — (1) Apparatus for the common use of several groups.
Balance, with weights, capacity, 100 to 150 grams, sen-
sitivity, 5 mg. (Note: If balance is to be used for
Physics 2 as well, one of greater capacity should be
Bottles, reagent, glass stoppers, 500 cc. capacity 10
Beaker, low form with lip, pyrex, capacity, 600 cc 1
Barometer, graduated in Metric scale, aneroid is re-
Files, triangular, 5" 3
Funnel, glass, dia. at least 80-100 mm. 1
Mortar and pestle, about 5 inches in dia 1
Thermometer, Centigrade, range, — 10° — 110°, solid
Platinum wire, length 3" long sealed in glass tubing.. 6 in.
Flask, Erlenmeyer, 500 cc, with generator fittings if
Kipp's Apparatus is not available (See below) 1
Furniture: (1) Tables for students* practical work in the labora-
tory. Suggestions re. construction: height, 36 inches;
width, 4 ft.; length, depends on requirements and space
available. Each group needs a space about four feet wide
and half the width of the table ; this gives about eight square
feet. A shelf along the centre of the table is convenient for
reagent bottles. Drawer and cupboard space for storing
apparatus in students' tables is needed and should be added
when finances will permit. If they are constructed with
locks, groups may be given sets of apparatus at the begin-
ning of the year and held responsible for it throughout the
year. (2) Cupboards, which will lock, are needed for stor-
ing chemicals and apparatus. (3) Demonstration table for
instructor, specifications, see above, width 21/^ to 4 ft.
B. — (2) Additional and more extensive apparatus which
should be included for large classes.
Kipp's gas generator, capacity of generating chamber, 500 cc. 1
Fume cupboard: As poisonous gases are very injurious for stu-
dents and teacher, a fume cupboard for the preparation of
such gases should be provided. Position, near demonstra-
tion table in the classroom so that it may be used convenient-
ly during instruction periods, as well as during laboratory
Size, at least two feet square; bottom of cupboard, 3 feet
from floor; height, about 3^/2 f^^t, that is, top, 6% feet from
Ventilation: If poisonous gases are to be prevented from entering
the room, this cupboard should be connected to the outside of
the building by means of a pipe. If it is not feasible to do
this through the heating or ventilating systems of the build-
ing, an electric fan may be found to be effective.
NOTE: Large classes will require additional quantities of the
apparatus listed under B (1) above.
(For class of six, i.e., three groups.)
NOTE: Even for classes as small as six, it will be found to be
more economical to buy in larger quantities than those given
Alcohol (for use in lamps) 1 pt.
Alcohol, denatured 1 qt.
Alum, pure powder 1 lb.
Aluminium foil or turnings 2 oz.
Aluminium Chloride C.P 1 oz.
Aluminium Nitrate C.P 4 oz.
Aluminium Sulphate C.P 2 oz.
Ammonium Carbonate C.P 4 oz.
Ammonium Chloride C.P 1 oz.
Ammonium Hydroxide C.P. 1 oz.
Ammonium Nitrate C.P 4 oz.
Ammonium Molydate C.P 1 oz.
Ammonium Sulphate C.P 4 oz.
Ammonium Sulphide Solution 4 oz.
Ammonium Sulphite C.P. 4 oz.
Ammonium Phosphate C.P. 4 oz.
Ammonium Thiocyanate C.P 2 oz.
Arsenious Oxide (Demon, only) , 1 oz.
Barium Chloride C.P 4 oz.-
Barium Nitrate C.P. 4 oz.
Bismuth Trichloride 1 oz.
Bleaching Powder 12 oz.
Borax, crystals 1 lb.
Calcium Carbonate, ppt 4 oz.
Calcium Carbonate, marble chips 1 lb.
Calcium Chloride C.P 4 oz.
Calcium Hydroxide, Tech 1 lb.
Calcium Nitrate C.P 1 oz.
Carbondisulphide 1 lb.
Carbontetrachloride 1 lb.
Charcoal, animal, powder 4 oz.
Charcoal, lumps or blocks 1 oz.
Chloroform, Tech 1 oz.
Cobalt Nitrate 1 oz.
Copper filings 4 oz.
Cupric Bromide 1 oz.
Cupric Nitrate C.P. 4 oz.
Cupric Sulphate, C.P., pow 1/2 lb.
Cupric Sulphate, Tech. % lb.
Cupric Chloride, C.P 4 oz.
Ferric Chloride, C.P. 4 oz.
Ferric Nitrate, C.P 4 oz.
Ferric Sulphate, C.P 4 oz.
Ferrous Chloride, C.P 4 oz.
Ferrous Sulphide, granular 8 oz.
Glucose, pure anhydrous 4 oz.
Hydrochloric Acid, C.P 1 lb.
Iron filings 1 lb.
Lead Nitrate, C.P 4 oz.
Lead Peroxide, Tech. 1 oz.
Lead Oxide (litharge) 4 oz.
Lead Oxide (red lead) 1 oz.
Lithium Chloride 1 oz.
Litmus, Best qual., gran. 1 oz.
Litmus paper, blue, vial of 100 strips
Litmus paper, red
Magnesium ribbon 1 oz.
Magnesium Carbonate, heavy 4 oz.
Magnesium Chloride, C.P. 4 oz.
Magnesium Nitrate, C.P 4 oz.
Magnesium Sulphate, C.P 8 oz
Manganese Dioxide, C.P 4 oz!
Manganese Dioxide, Tech. 1 ib*
Mercury metal i qz*.
Mercuric Chloride, C.P ........".. 1 oz!
Mercuric Nitrate, C.P 1 oz!
Mercurous Nitrate, C.P. 1 oz!
Methyl Orange i/^ oz!
Nitric Acid, C.P 1 lb.
Nickel Chloride 1 ©z!
Phenolphthalein 1 oz.
Portland Cement 4 oz!
Potassium Bromide, C.C. or U.S.P 4 oz!
Potassium Carbonate, C.P 4 oz.
Potassium Chlorate, C.P., pow. 4 oz.
Potassium Chloride, C.P 4 oz.
Potassium Chromate, C.P ,. 4 oz.
Potassium Ferricyanide, C.P. 1 oz.
Potassium Ferrocyanide, C.P 4 oz.
Potassium Iodide 1 oz.
Potassium Nitrate, C.P. 4 oz.
Potassium Permanganate U.S.P 4 oz.
Potassium Phosphate, C.P 4 oz.
Potassium Sulphate, C.P 4 oz.
Potassium Sulphite, C.P 4 oz.
Silver Nitrate 1 oz.
Sodium Acetate Anhy 1 lb.
Sodium Bicarbonate, C.P 1 lb.
Sodium Carbonate, Tech., pow. 8 oz.
Sodium Chloride, C.P 1 lb.
Sodium Hydroxide, C.C. sticks or pellets 4 oz.
Sodium Nitrate, C.P., pow. 1 lb.
Sodium Peroxide, pow. 4 oz.
Sodium (Disodium) Phosphate, C.P. 4 oz.
Sodium Sulphate, C.P 4 oz.
Sodium Sulphite, C.P 4 oz.
Sodium Sulphide, C.P 4 oz.
Sodium Thiosulphate 4 oz.
Starch, corn 4 oz.
Strontium Chloride, C.P 1 oz.
Sulphuric Acid, C.P 1 lb.
Zinc, C.P. (low in As.), gran 1 lb.
Zinc Chloride, C.P 2 oz.
Zinc Nitrate, C.P 4 oz.
Zinc Sulphate, C.P 4 oz.
Zinc Sulphide, Tech 4 oz.
NOTE: The above list includes small quantities of a variety of
salts which may be used as "unknovnis** in Exercises 51
Equivalents: 28.3 grams=l oz.; 1 pound=453.6 grams.
D. — Materials which may be obtained locally.
(For class of six, three groups.)
Candles, paraffin, for demonstration 2
Clay, well pulverized ^A lb.
Clock spring, 1/8" wide 1 ft.
Commercial soap, 3 or 4 cakes.
Copper sheet, medium gauge, 17 sq. in. cut into
strips about 3" x 3/8".
Zinc sheet or new galvanized iron, same as above.
Distilled water 1/2 gal.
Finger bandaging, 2" wide 1 yd.
Glass (window) cut in 3" squares 6 squares
Honey 1 oz.
Iron nails, bright, 11/2-2" 6
Lard or other fat 1 lb.
Lime (quicklime) 1 lb.
Molasses, black 2 oz.
Red calico '. 1/8 yd.
Sugar, cane or beet 28 gm.
Wooden splints^ — 6"-8" long 2 doz.
Oatmeal 1 oz.
Vegetable oil (olive, peanut, etc.) 1 oz.
Vinegar 1 oz.
LIST OF EXPERIMENTS
N.B. — References are made to chapters and pages of the
1. BROMINE AND IODINE
Bromine and iodine may be prepared by the students (p.
159), but it is suggested that these and chlorine water (p. 150)
be prepared in advance by the teacher. Sodium salts may be
substituted for potassium salts in this exercise.
Apparatus — Test tubes and rack. Burner.
Materials — Potassium chloride. Potassium bromide. Po-
tassium iodide. Chlorine water. Bromine water. Silver nitrate
solution. Ammonium hydroxide. Sulphuric acid (1 of acid to 2
of water). Manganese dioxide. Carbon disulphide or carbon
tetrachloride. Alcohol. Iodine crystals. Starch. Tincture of
Tests for a chloride, a bromide and an iodide.
1. To a concentrated solution of each of (1) potassium brom-
ide, (2) potassium iodide, in separate test tubes, add a few cc. of
chlorine water (p. 162). Colours? Equations?
2. Half fill three test tubes with a dilute solution of a chlor-
ide, a bromide and an iodide, respectively. To each add a few
drops of silver nitrate solution (p. 156). Colours? Equations?
3. After allowing the precipitate formed in (2) to settle,
pour off the supernatent liquid. To each precipitate add about 5
cc. of ammonium hydroxide. Shake. Result?
4. Prepare a precipitate of silver chloride and let stand for
a few minutes in a strong light. Result?
5. Into each of three test tubes pour about i/^ cc. of sul-
phuric acid. (If not previously prepared by the teacher, this acid
can be prepared by adding, slowly and carefully, 1 part of sul-
phuric acid to 2 parts of water) . Into the first test tube pour
about % cc. of a mixture of potassium chloride and manganese
dioxide. To the second add a similar amount of a mixture of
potassium bromide and manganese dioxide, and to the third add
a mixture of potassium iodide and manganese dioxide. Warm
each test tube gently if no reaction is visible (p. 159). Colours?
Solubility of halides.
6. Dissolve a pinch of (1) potassium bromide in 5 cc. of
water, and of (2) potassium iodide in 5 cc. of water. To each
add about 2 cc. of carbon disulphide or carbon tetrachloride.
Shake and allow to stand. Now to each test tube add a little
chlorine water and shake. Again allow to stand (p. 162). Re-
7. Into four test tubes put about 2 cc. of water, alcohol, car-
bon disulphide, potassium iodide solution, respectively. Drop a
small crystal of iodine in each and shake (p. 162) . Tabulate the
colours and solubilities.
Test of iodine.
8. (a) To a solution of starch (obtained by boiling, if neces-
sary,) add a few drops of tincture of iodine. Result?
(b) To a solution of potassium iodide add a little starch
solution. Result? Now add to this solution chlorine water.
9. Put a small crystal of iodine in a test tube. Heat. Result?
2. HYDROCHLORIC ACID
Apparatus — Test tubes and rack. Beaker. Stirring rod.
Burner. White Paper.
Material — Hydrochloric acid. Sodium hydroxide. A second
acid. A second base. Litmus. Phenolphthalein. Methyl orange.
Sulphuric acid. Potassium chloride.
1. Action of Indicators.
Half fill each of six test tubes with water. Number 1 to 6.
To numbers 1, 3 and 5 add a few drops of diluted hydrochloric
acid, and to numbers 2, 4 and 6 pour a few drops of sodium
hydroxide solution. Into 1 and 2 pour a few drops of litmus
solution, into 3 and 4 a little phenolphthalein, and into 5 and 6
methyl orange. Repeat the experiment using a different acid and
base (p. 218). Tabulate your results, as indicated below:
Into a beaker half full of water, add about 3 cc. of dilute sod-
ium hydroxide solution. Add several drops of phenolphthalein.
Stir. Place a sheet of white paper under the beaker. Now add
slowly, while stirring, dilute hydrochloric acid till the colour just
disappears. On the addition of a single drop of base the colour
should begin to reappear. Explain. Equation? (See page 218.)
3. Test for hydrogen chloride.
Pour 1/2 cc. of concentrated sulphuric acid into a test tube
and add a large pinch of potassium chloride. Warm gently and
breath across the top of the tube. Result? (See page 221.)
(The fumes observed are due to the condensation of moisture
in the breath, as it dissolves in the gas generated.)
4. Solubility of hydrogen chloride gas.
Put about 1 cc. of hydrochloric acid into a test tube fitted
with a one-hole stopper in which is a piece of glass tubing about 3
inches long, open at both ends. Boil the acid till, on breathing
over the end of the tubing, white fumes appear. Invert the test
tube and quickly immerse the tubing in a beaker of water.
3. SODIUM HYDROXIDE
Test tubes and rack. Delivery" tube. Collecting
Materials — Caustic soda (sticks or pellets). Copper sul-
phate. Ferric chloride. Lead nitrate. Ferrous sulphate. Al-
uminum sulphate. Chalk or limestone. Ammonium chloride.
Observe a small piece (l^ inch of stick) of caustic soda. (Do
not handle.) Allow it to remain exposed to moist air for a few
moments. Result? Drop the piece in about 2 cc. of water in a
test tube. Note any change in temperature as it dissolves. Now
dilute the solution with about 15 cc. of water. Rub a little of this
solution between the finger and thumb. (Feel?) (See page 226.)
2. Precipitating reagent.
Into separate test tubes, pour about 10 cc. of each of the fol-
lowing solutions: copper sulphate, ferric chloride, lead nitrate,
ferrous sulphate, aluminum sulphate. To each solution add a
few drops of the solution prepared in (1) . Results? Equations?
Now add 2 or 3 cc. of the basic solution to each of the test
tubes. Results ?
3. Reaction with an anhydride.
Prepare a test tube of pure carbondioxide. Invert it in a
concentrated solution of caustic soda in a beaker, and allow to
stand. Agitate a little if necessary to speed up reaction. Result?
Equation? (See page 229.)
4. Test for ammonium radical.
Into a test tube place a pinch of ammonium chloride (or
other ammonium salt) . Add about 1 cc. of caustic soda solution
and warm. Odour? Equation?
Repeat this experiment but use a few cc. of a solution of an
ammonium salt instead of the solid as above. Result?
Apparatus — 2 Burettes (50 cc). Clamp. Stand. Beaker.
Materials — Hydrochloric acid (1 of acid to 100 of water).
Sodium hydroxide solution (1/10 Molar). Phenolphthalein.
Set up two clean burettes (preferably 50 cc.) fitted with
clamp or tap, on a stand. Fill burette A with hydrochloric acid
(previously prepared by the teacher— 1 of acid to 100 of water) .
Fill burette B with approximately .1 ( = 1/10) molar sodium hy-
droxide solution (previously prepared by the teacher). Run a
little acid and base out of each burette into a beaker. Discard
this liquid. Now make careful readings of the amount ot acid
and base in the burettes, by observing the position of the bottom
of the meniscus, read at eye level. Record these readings.
Into the beaker run about 20 cc. of the acid. Add several
drops of phenolphthalein solution. Keep a sheet of white paper
under the beaker to aid in detecting colour changes. Place the
beaker under burette B and run out about 10 cc. of the basic solu-
tion, stirring constantly. Continue to add the basic solution,
drop by drop, stirring carefully. When the addition of a single
drop of sodium hydroxide will produce a permanent pink colour,
which disappears by the addition of a drop of the acid, the neu-
tralization is complete. This titration is said to have reached the
Take the readings from the burettes. Calculate the volume
of each solution used. Assuming the basic solution to be, 0.1
normal (or 0.1 molar) , calculate the weight of hydrogen chloride
in 1 liter of solution used. Calculate also to 2 decimal places the
normality of the acid solution, using the formula
Va X Na = Vb X Nb
when V = volume
N = normality
A = acid
B = base
(Va would read "Volume of acid".)
Apparatus — Glass plate. Test tubes and rack.
Materials — Tartaric or oxalic acid. Slaked lime. Litmus.
1. Effect of moisture on acid and basic reactions.
Place a clean, dry glass plate on a sheet of white paper. On
the plate place separately a pinch of dry tartartic or oxalic acid,
and a little slaked lime. Test the acid and lime with separate
pieces of dry red and blue litmus. Result?
Now moisten each of these substances with a drop or two of
water. Again test with the litmus papers. Results? Expla-
2. Effect of dilution upon ionization.
Into each of 3 dry test tubes put a small quantity (about 1
cc.) of copper sulphate (powdered), copper chloride and copper
bromide, respectively. In this exercise observe carefully for col-
our changes. To each test tube add one or two drops of water,
then slowly add more water till no further colour change occurs.
The final colour should be a light blue. Tabulate your results in
the following form :
Write equations indicating the ionization.
3. Reversible reaction.
To a solution of sodium carbonate in a test tube, add some
potassium nitrate solution. Any reaction? Explain. Equation?
Into a beaker put about 1 grain of bismuth trichloride. Add
a drop or two of hydrochloric acid. If necessary add a little
more, just enough to dissolve the salt. Now add water slowly,
stirring constantly till a definite change occurs. Result? The
equation for the reaction is
BiCla +H2O BiOCl + 2HCl.
The bismuth oxychloride is insoluble.
Now add dilute hydrochloric acid till the reaction is com-
4. Cominan ion effect.
Make a strong solution of sodium chloride in water, in a test
tube, and then add about an equal amount of hydrochloric acid.
What happens? Can you account for the result?
Apparatus — Test tubes and racks.
Materials — Litmus. Several salts.
1. Litmus reactions on solutions of salts.
Into separate test tubes put a pinch of each of the following
salts : sodium chloride, ferric chloride, copper sulphate, potas-
sium nitrate, sodium carbonate, ammonium sulphate, sodium bor-
ate (borax). To each test tube add about 5 cc of water and
shake. Drop a small piece of red and of blue litmus into each
solution. Examine the litmus. (See page 260.)
Tabulate your results as indicated below :
Red to blue
2. Write an equation for each of the above reactions which
did not show a neutral effect on litmus. (See page 261.)
3. Write an ionic equation corresponding to each equation
7. FLAME TESTS
Apparatus — Platinum (or nichrome)
wires. Burner. Co-
Material — Salts of sodium, potassium, lithium, calcium, bar-
ium, strontium, copper. Dilute hydrochloric acid.
For this experiment it is desirable to have a platinum wire
for use v^ith each salt tested. In this case, the glass tube (in the
end of which the platinum v^ire is held) should be inserted
through a one-hole stopper. This stopper is then inserted into
the test tube, and the test tube labelled with the name of the solu-
tion it contains. The wire should reach into the liquid. Since
this arrangement makes it possible to test only this one salt on
this wire, time need not be lost in cleaning the wire after every
test. If separate wires are not available, the platinum wire may
be cleaned after testing a salt by alternately dipping it into a
little clean dilute hydrochloric acid, and heating, until all trace
of the colour of the salt tested has disappeared.
Test — Remove the wire from the solution in the test tube and
hold it at the edge of a colourless flame. Colour ? Repeat several
times. Observe flames of the following salts through a cobalt
glass in addition to the regular tests : Sodium, potassium, a mix-
ture of sodium and potassium (p. 403) . Put the corner of a cop-
per wire gauze into a little dilute hydrochloric acid and hold in a
colourless flame. Result? Powder a little blackboard chalk and
apply the flame test. Colour? Clean the wire thoroughly (if
necessary) at the end of each test.
A salt of strontium may be tested if desired.
Record your results in the following form :
Apparatus — Test tubes and racks.
Burner. Beakers (2)
Materials — Aluminum foil. Hydrochloric acid. Sodium
hydroxide solution. Splint. Aluminum sulphate. Ammonium
hydroxide. Lime water. Charcoal block. Cobalt nitrate solu-
tion. Cotton cloth. Logwood.
1. Action of strong acid and base
Into each of two test tubes put about 1 sq. cm. of aluminum
foil. To one add about 2 cc. of hydrochloric acid (concentrated) ,
and to the other some caustic soda solution. Warm gently for a
few moments. Results? Equations?
Test any gas that is generated, with a burning splint. Re-
sult? (See page 415.)
2. Action of caustic soda on aluminum hydroxide.
Half fill each of two test tubes with a solution of aluminum
sulphate. To the first add a few drops of ammonium hydroxide
solution, then several cc. Result? Equation?
To the second add a little caustic soda solution, then an ex-
cess. Result? Equations?
3. Purification of water by aluminum hydroxide.
Prepare some murky water by stirring a handful of soil in
water. Allow the mixture to stand a few minutes. Then pour
off some of the cloudy water into each of two beakers. To one
add about 2 cc. of alum solution or solution of aluminum sulphate,
and then several cc. of lime water. Allow to stand and observe
at five minute intervals. The second serves as a control for pur-
poses of comparison. Results? Equation? (See page 420.)
4. Test for aluminum ion.
Using a small coin, wear a depression near one end of a char-
coal block. Fill this with some aluminum compound (moistened
to a paste) and heat with the oxidizing flame of a blowpipe.
Moisten the residue with a few drops of cobalt nitrate solution.
Heat strongly again. A blue colour indicates aluminum.
5. Aluminum hydroxide as a mordant.
Cut two pieces of white cotton cloth. Mordant one by soak-
ing it in a solution of aluminum sulphate and then in ammonium
hydroxide, squeezing out the excess liquid after each soaking.
Now place both pieces of cloth in a beaker containing logwood or
alizarin solution. Boil for a few minutes. Wash the cloths and
examine. Results? Equation? (See page 635.)
Apparatus — Test tubes and racks.
Material — Several salts. Nail. Potassium ferrocyanide.
Ammonium hydroxide. Copper strip. Silver nitrate solution.
An iron salt.
1. Colour of cupric ion.
Dissolve, in separate test tubes, small quantities of copper
sulphate, copper chloride, copper bromide, sodium chloride and
potassium nitrate. Colours?
Write ionization equation for each of the above and state
the colour of each ion formed. (See page 459.)
2. Tests for copper ion.
Place a clean nail in a solution of copper sulphate. Allow to
Add some potassium ferrocyanide solution to a dilute solu-
tion of copper sulphate. Result? Equation?
Add ammonium hydroxide solution, drop by drop, to a solu-
tion of copper sulphate, till no further change occurs. Results?
Equations? (See page 459.)
Suspend a strip of copper in silver nitrate solution in a test
tube. Observe frequently. Results? Equation?
Try another strip of copper in a solution of an iron salt. Re-
sult? (See page 396.)
10. ZINC AND SILVER
Apparatus — Charcoal block, blow pipe, beaker.
Materials — Hydrochloric acid, zinc pellet, nail, sodium car-
bonate, aluminum foil, badly tarnished piece of silverware, silver
ring or dime.
Scoop a hole in the charcoal block and place zinc pellet in
Take the nail and dip it into the concentrated hydrochloric
acid. Why? Explain. (See page 220.)
Heat the zinc pellet using the blowpipe and, while the zinc is
molten, thrust the nail into it. What do you notice after the nail
is removed? Explain. (See page 467.)
2. Cleaning Silverware.
Make a solution of sodium carbonate (10 grams of sodium
carbonate in about 100 cc. of water) . Heat the solution to boil-
ing point. Place the aluminum foil in the bottom of the beaker
and the tarnished silver article in contact with the foil. Heat
the beaker for a period of twenty minutes or longer. Remove
the article, wash and dry.
What do you notice? Explain, writing the necessary equa-
tions. (See page 469.)
11. BAKING POWDERS
Apparatus — Test tubes and racks. Stand. Clamp. Deliv-
ery tube. Burner. Beakers (250 cc).
Materials — Baking soda. Lime water. Cream of tartar.
Dilute hydrochloric acid.
1. Action of heat on baking soda.
Put about 2 grams of bicarbonate of soda in a test tube and
support this in an almost horizontal position on a stand. Ar-
range a delivery tube so that it leads into lime water in a test
tube. Heat the bicarbonate gently. Result? Equation? (See
2. Action of a strong acid on baking soda.
Into a test tube put a small quantity of sodium bicarbonate.
Have a stopper and delivery tube arranged as in part (1). Add
a few drops of dilute hydrochloric acid to the salt and replace the
stopper quickly. Result? Equation? (See page 366.)
3. Reaction of a baking powder.
Weigh out 2 gr. of potassium bitartrate (cream of tartar) .
Calculate the weight of sodium bicarbonate needed to react with
it (p. 365) . Weigh out this quantity and mix the two salts. Put
half the mixture into a beaker containing 100 cc. of cold water,
and the other half into 100 cc. of hot water. Results? Equa-
12. CALCIUM COMPOUNDS
Apparatus — Test tubes and racks. Wire gauge. Burner.
Evaporating dish. Broken test tubes.
Materials — Chalk. Litmus. Plaster of Paris. Quick lime.
Sand. Portland cement. Hydrochloric acid. Lime water.
Place a piece of marble or chalk about the size of a pea on a
wire and heat strongly for 20 minutes. Allow to cool. Now put
it in a test tube and add a little water. Note any temperature
change. Test with red and blue litmus. Result? Equation?
(See page 511.)
2. Plaster of Paris.
Put a heaping tablespoonf ul of Plaster of Paris in an evap-
orating dish. Add just enough water to make a thick paste.
When hardened to the proper consistency, mould rapidly into any
desired shape. Allow to harden. Equation? (See page 516.)
Mix together small quantities of quicklime and sand in the
proportions of 1 to 2 by volume. Add water to make a thick
paste. Pour into a broken (useless) test tube and allow to stand
for a week. Break away the test tube and examine. Result?
(See page 515.)
Mix some Portland cement and fine sand in the proportions
of 1 to 3 by volume. Add enough water to make a thick paste.
Pour into a broken test tube or paper box and allow several days
to harden. Result? (See page 551.)
5. Hard water.
Pass carbondioxide (prepared by the action of an acid on a
carbonate) into lime water till the precipitate at first formed
clears. Equations? Now boil some of this clear water. Result"?
Equation? (See page 521.)
13. COMPOUNDS OF IRON
Apparatus — Test tubes and rack. Burner.
Materials — Ferric salts. Ferrous salts. Sodium hydroxide.
Ammonium thiocyanate. Potassium ferrocyanide. Potassium
ferricyanide. Nitric acid. Dilute sulphuric acid. Steel wool.
Dilute hydrochloric acid.
1. Tests for a ferrous salt.
Half fill each of four test tubes with a dilute solution of a
ferrous salt (freshly prepared). Into the test tubes put, res-
pectively, a few drops of the following solutions: Sodium hy-
droxide, ammonium thiocyanate, potassium ferrocyanide, and
potassium ferricyanide. Colours? Equations? (See page 529.)
2. Tests for a ferric salt.
Repeat the procedure outlined in (1) but use a ferric salt
instead of a ferrous salt in the original test tubes. Colours?
Tabulate the results of (1) and (2) in the form shown be-
low, giving the name of the salt formed, its formula and its col-
our. Indicate any precipitates formed by an arrow (pointing
3. Oxidizing a ferrous salt.
To 5 cc. of a solution of ferrous sulphate, add 1 cc. of dilute
sulphuric acid, and then a few drops of nitric acid (concen-
trated). Boil (CAUTION!). Test a small quantity of the re-
sulting liquid for ferrous and ferric ions. Result? Equations?
(See page 527.)
4. Reducing a ferric salt.
To 10 cc. of a solution of ferric chloride add several strands
of steel wool (or mossy zinc). Pour in 2 or 3 cc. of dilute hy-
drochloric acid. Warm gently. Test small quantities of the so-
lution from time to time for ferrous and ferric ions. Result?
Equation? (See page 527.)
14. BORAX BEAD TESTS (Optional)
Apparatus — Burner. Platinum wire. Metallic compounds
to be tested.
Ordinary borax (hydrated sodium tetraborate) swells when
heated owing to the evaporation of the water of crystallization,
then melts to a colourless glassy bead, containing the oxide of
boron, B2O3. This oxide combines when heated with several
metallic oxides imparting characteristic colours, by which the
metals are identified. (See page 555.)
Bend the end of a platinum wire around the end of a pencil
into a loop about 3 mm. in diameter. Heat the wire, and while
still hot dip it into some powdered borax. Again heat strongly.
Continue the process till a globular bead has been formed.
1. Oxidizing flame.
Pour a little cobalt nitrate on a watch crystal. Touch the
bead while hot to a tiny particle of cobalt nitrate. Heat in the
oxidizing (outer) flame of the burner till the bead is red hot and
the colour uniform. Observe the colour while hot, and when cold.
If the bead is too dark, repeat using less of the nitrate. To clean
the bead, dip while hot into water and brush the particles away.
Forming a new bead each time, test the following com-
pounds: Ferrous sulphate, manganese dioxide, nickel nitrate,
chromium sulphate. Other compounds of these metals may be
2. Reducing flame. Repeat the experiment using the reduc-
ing flame (tip of the inner cone) .
Tabulate your results as shown below :
3. Clean the bead when you have completed the tests.
Apparatus — Large pyrex test tube, outlet tube, stoppers,
gas jars, pneumatic trough, mortar and pestle.
Materials — 8 gm. anhydrous sodium-acetate, 10 gm. soda-
lime, dilute solution of potassium permanganate.
1. Preparation of Methane.
Mix THOROUGHLY in a mortar, 8 gm. of anhydrous
(fused) sodium-acetate and 10 gm. of soda-lime. Introduce the
mixture into a large pyrex test tube and attach a glass outlet
Heat the test tube gently, at first, and then more strongly
until an evolution of gas takes place. After the air in the test
tube has been displaced, collect (over water) several jars of the
• Calculate how many cc, of methane (under S.T.P. See note
page 32) should theoretically be obtainable from 8 gm. of sod-
Write the equation for the reaction.
2. Properties of Methane.
Test methane for inflammability by applying a flame to the
mouth of one of the jars of the gas. Explain the lack of lumin-
osity to the flame.
Allow the gas to bubble into one of the gas jars until it is
one-tenth full of the gas. Keep the jar inverted and permit the
air to fill the remaining part. Apply a flame to the mouth of the
jar containing the methane-air mixture. Why is the action rapid
in this case? Write the equation for the reaction and calculate
how much air (20 per cent oxygen) would be required to oxidize
10 cc. of methane.
Shake a few cc. of a .3 % solution of potassium permangan-
ate in a jar of methane gas. Note whether the permanganate
solution changes colour. If the methane gas as prepared, contains
small amounts of easily oxidized impurities, what effects may
they have on this test?
16. DETERMINATION OF ACIDITY OF VINEGAR
Apparatus — Burette (50 cc.) Pipette (10 cc.) Ring stan-
dard clamp, beaker (250 cc.) .
Materials — Vinegar or cider. Distilled water. O.IN solu-
tion of sodium hydroxide. Phenolphthalein solution.
(For this experiment a O.IN solution of sodium hydroxide
should be prepared in advance as follows: Dissolve 4 grams of
caustic soda in distilled water. Dilute to 1 liter. Stir well.)
Using the pipette, put exactly 10 cc. of the vinegar (or cider)
into a beaker. Add about 50 cc. of water. Add a few drops of
phenolphthalein. Fill the burette with the sodium hydroxide so-
lution and titrate by running the basic solution into the beaker,
drop by drop, till the end point is reached (as in exp. 4) . Record
the volume of base used (final reading minus first reading in the
Repeat the titration and again record the volume of base
Concentration of sodium hydroxide solution O.IN
Wt. of sodium hydroxide in 1 cc. of solution 0.004 g.
Volume of basic solution used :
first titration ■..cc.
second titration cc.
Weight of acetic acid in 10 cc. of vinegar g.
Weight of acetic acid in 100 cc. of vinegar g.
Normality of vinegar
Apparatus — Beakers, evaporating dish, ring and stand, wire
Materials — 12 gm. of lard or other fat, 25 cc. denatured alco-
hol, 3 gm. of sodium hydroxide, 3 or 4 brands of commercial soap.
1. Manufacture of soap.
Weigh 12 gm. of lard or other fat. Place it in a beaker and
add 12 cc. of alcohol, and 3 gm. of sodium hydroxide dissolved in
12 cc. of water.
Set the beaker in a second larger beaker containing hot
water. Stir the mixture frequently and continue heating for an
After this, add 100 cc. of a saturated salt solution. Cool the
mixture and filter it through a double thickness of cheesecloth.
Rinse the soap in the filter with 50 cc. of cold water. Press the
soap in a small dish which will serve as a mold.
2. Some properties of certain soap solutions.
Dissolve small chips of commercial soaps in different beak-
ers, using 10 cc. of water.
To each, add a small amount of phenolphthalein.
Compare degrees of alkalinity.
Should soaps be strongly alkaline? Explain.
3. Insoluble soaps.
Test the reaction of a soap solution with solutions of copper
sulfate, magnesium sulfate, zinc chloride, calcium chloride.
What salts are present in hard water? Name some insoluble
soaps and give their uses.
4. Emulsifying Power of Soap.
Shake 3 or 4 drops of cotton seed oil, corn oil or olive oil
with 10 cc. of a solution of soap. Is an emulsion produced?
Explain how soap cleans.
18. FOOD INGREDIENTS
Apparatus — Test tubes and rack. Burner. Mortar and
pestle. Porcelain crucible cover.
Materials — Starch. Glucose. Cane Sugar. Fat. Oil. Egg.
Oatmeal. Cheese. Iodine solution. Fehling's solution. Hydro-
chloric acid. Sodium carbonate. Litmus. Benzine. Nitric acid
(cone). Ammonium hydroxide.
1. Test for starch.
Put a pinch of starch in a test tube. Half fill with water.
Shake and boil. Cool and add a drop of iodine solution (diluted
tincture of iodine in potassium iodide solution). Colour? (See
page 602). Test freshly cut pieces of potato and bread with
2. Test for sugar.
Dissolve 1 cc. of glucose in 10 cc. of water. Add 5 cc. of Feb-
ling's solution and boil for a few minutes. The red precipitate
formed is a test for glucose or fructose. (See page 603.)
Repeat using a solution of cane sugar (sucrose). Result?
Now add a few drops of dilute hydrochloric acid to a solution of
cane sugar in a test tube. Heat to boiling. Cool. Now neutral-
ize by adding a little powdered sodium carbonate (test with lit-
mus). Test as above with Fehling's solution. Result? (See
3. Test for fats and oils.
Place a drop of oil on a piece of paper. Hold to the light.
Put a spoonful of cornmeal or crushed peanuts in a test tube.
Keeping away from a flame, add enough benzine or ether to cover.
Shake. Allow to stand. Pour a few drops of the clear liquid on
a piece of paper. Examine against the light. Result? (See
4. Test for proteins.
Place a little of the white of a hard-boiled egg in a test tube.
Add a few drops of nitric acid (cone). Colour? Wash off the
acid with water. Add a few drops of ammonium hydroxide.
Colour? (See page 608.)
5. Test for mineral matter.
Place half a teaspoonful of oatmeal on a porcelain crucible
cover. Heat strongly (under a hood) , till all the carbon is burned
Samples of food such as bread, cheese, beans, lean meat, can
be tested for each of the above ingredients. If these tests are
made, tabulate your results.
EXAMINATION FOR THE ACID RADICLE
The following scheme is for the identification of the anions :
Carbonate (CO 3), sulphite (SO3 ), sulphide (S ), chloride (CI ),
bromide (Br ), iodide (I), nitrate (NO3), phosphate (PO4),
sulphate (S07), nitrite (NO2 ).
To a portion of the original solution, add dilute HNO3. No
gas evolved. Pass on to Group B.
If a gas is evolved :
(1) Gas is odourless — ^test with lime water. If carbondioxide
is present, this indicates a carbonate.
(2) Gas has sharp odour — SO2 — a sulphite.
Confirm by holding a drop of K2Cr04 on a glass rod in
the gas — drop turns pale green.
(3) Gas has odour of rotten eggs — a sulphide.
Confirm by holding paper soaked with lead acetate solu-
tion in gas. Paper turns brownish-black.
To a portion of original solution, add AgN03 solution. No
ppte. Pass on to Group C.
A ppte. is produced:
(1) White ppte. — a chloride.
Confirm by adding NH4OH in excess. Ppte. dissolves.
(2) Cream-coloured ppte. — a bromide.
Confirm by adding a little Mn02 and cone. H2S04to
original solution and warming. Brown fumes of
(3) Yellow ppte. — an iodide.
Confirm with Mn02 and H2SO4 as above.
Violet vapors of iodine.
Place a square of clean glass on a sheet of white paper on
the desk. On the glass put close together a drop of the solution
to be tested, a drop of ferrous sulphate solution and a drop of
cone. H2SO4. With a glass rod bring these together. A brown
colour (not to be confused with the shadow of the liquid on the
paper) — a nitrate. Note: The brown-ring test as given on page
288 of your text may be substituted.
No brown colour, pass on to Group D.
Confirm by adding a little cone. H2SO4, and some copper
turnings to original solution. Warm. Brown fumes.
To about 2 cc. of ammonium molybdate in a test tube, add
about 1 cc. of original solution to which a little HNO3 has been
added. If no immediate reaction, warm a little (do not boil) and
allow to stand.
No yellow ppte. Pass on to Group E.
Fine yellow ppte. — a phosphate.
Confirm by adding AgNOs to original (neutral) solution.
Yellow ppte. soluble in HNO3 or in NH4OH.
To a portion of the original solution add BaCl2 and dilute
White ppte. — a sulphate.
Confirm by boiling. Ppte. remains.
If the salt is insoluble in water treat as follows :
Put a small quantity of the salt in a test tube and add a little
cone. H2SO4. Warm.
(a) Gas colourless — identify as in Group A above,
or if cloudy fumes are produced on breathing across
mouth of test tube — a chloride.
(b) Gas brownish — a nitrite.
After trying several of the tests, ask your teacher for an
unknown salt (solid) . Use part of this salt for determination of
the cation and part for determination of the anion. Keep a com-
plete record of the tests you make, recording all negative as well
as positive results.
In case of an accident or injury, notify your instructor at
Treatment for common types of injuries in the laboratory.
On the skin — Wash with plenty of water. If severe, dress
with a paste of sodium bicarbonate.
On the clothing — Saturate with dilute ammonium hydroxide.
Internal — Drink lime water, milk of magnesia or baking
On the skin or clothing — Wash with plenty of water. Then
apply a boric acid solution. Wash again.
Internally — Drink juice of a lemon or orange.
Apply a paste of sodium bicarbonate and water.
Clean with water. Apply tincture of iodine or hydrogen
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The following exercises are designed to aid the student of
Biology in carrying out a number of individual experiments. It
is not expected that all those listed should be completed, but an
effort should be made to perform as many as possible. Nor is it
intended that they should replace those outlined in the textbook.
Many of these, also, should be performed by the student. Stu-
dents should be encouraged to learn much of their Biology from
actual observations, rather than by merely reading the textbook.
Many of the details of the experiments may be modified to
suit the local conditions.
Blueprints make accurate and permanent records of many
The teacher should v^rite for "Turtox Leaflets," supplied free
by the General Biological Supply House, Chicago. These give
very helpful instructions on such items as "Mounting Insects,"
"Making an Aquarium," "The Feeding of Minute Animal Organ-
isms," etc. The catalogue of this Supply House is most helpful to
teachers of Biology, and may be obtained upon request.
LIST OF APPARATUS AND MATERIALS
Beakers, 400 cc.
Beakers, 250 cc.
Chemicals — i^
Cover slips (for microscope slides)
Flower pots, 3"
Flower pots, 4"
Jars (of various sizes)
Microscope (with high power and low power)
Vials (wide mouth, glass)
OUTLINE OF PRACTICAL WORK
1. USE OF THE MICROSCOPE
1. Learn names of the parts of the instrument; e.g., stage,
aperture, diaphragm, mirror objective, eyepiece, etc. There
should be screws for coarse and for fine adjustment. Mirror
should have plane and concave sides.
2. Preparation of object for viewing:
The object must be transparent, a very thin section of plant
or animal tissue, or protozoans, aphids, water fleas, moulds,
Place the object on a clean glass slide ; place a drop of clean
water on it (dry specimens do not transmit light efficiently),
cover with a cover glass.
3. Place the specimen prepared as above on the stage, and
centre it over the aperture.
4. Turn the mirror below the stage toward the source of
light. If the light comes from a window, use the plane side of
mirror; if from a lamp flame or filament, use the concave side.
Tilt the mirror until you see the beam of light pass through
the glass slide and specimen.
5. See that the low-powered objective is in place above the
specimen. With your eye on the level of the stage, turn the ob-
jective down until it almost touches the cover-glass. (Never turn
screws to lower objective, with your eye to the eyepiece, unless
the specimen is plainly in view.)
6. Now place your eye above the eyepiece. Light should be
coming through to your eye. Turn the screws to raise the ob-
jective. Continue until image of specimen comes into view.
7. Now that you have the specimen in view, several im-
provements may be made. Experiment with mirror and with
diaphragm until you have the best possible light arrangement.
With eye still placed to the eyepiece, take the slide on which
specimen is placed in both hands and move it gently back and
forth to view different parts of specimen.
8. If you desire a higher magnification, there are several
methods you may adopt. You may replace the eyepiece with one
of higher power. You may raise the eyepiece by lengthening the
tube between objective and eyepiece and then re-adjusting the
focus. Or you may replace the objective with one of higher
power. For the high power objective you will need more light.
2. THE AQUARIUM
Every biology classroom should have an aquarium. Com-
plete instructions on making one will be found in ''Everyday
Biology," pages 636-8. Water weeds may be anchored to the bot-
tom by tying a glass stopper or a piece of glass tubing to the
lower end of the plant. Roots should soon strike into the sand.
In addition to fish, snails should be present. If the aquarium is a
large one, salamanders may also be stocked. However, these
have a tendency to attack the fish, and so are better kept by them-
selves. If it is desired to hatch frog tadpoles from eggs, or young
snails from eggs, the fish must be removed. If the water be-
comes m.urky, it probably indicates the presence of too many
''Everyday Biology" also gives directions for the making of
a terrarium (page 645). A desert terrarium, including a few
cacti and "horned toads," makes a very interesting display.
"Horned toads" (lizards) may be obtained from the Biological
Supply House, Chicago.
3. MICROSCOPIC ORGANISMS
(For all students)
Materials: Small quantity of organic matter: a handful of
grass, dry hay, dead leaves, slices of carrot, etc.
Procedure: Place any of the above in a jar of water and
leave in a warm place, 70-90 degrees Fahrenheit, for several
Take a clean glass slide. Place upon it a drop of clean water.
Pluck a few threads from an old piece of clean cotton and pick
them apart with a needle until the fibres are very finely divided.
Place these in the drop of water on the slide. These fibres form
a trap which restricts the movements of the protozoa and allows
the observer to keep them in view.
Now take a sample of the infusion from the jar and place a
drop of it among the wet fibres. Cover with thin glass. Exam-
ine with the low power objective of the compound microscope.
There are certain to be paramecia and other ciliata, and you
may be fortunate enough, if your infusion was made with decay-
ing leaves, to find amoebae. The latter are more likely to be
found at the bottom of the jar.
Water from Sloughs and Ponds —
Samples should be collected from as many of these sources
as possible. If there is a green scum on the water there are sure
to be algae, such as closterium, ulothrix, spirogyra.
On the edges of leaves under water, the protozoan, vorticella,
is usally found. Place the wet leaf on a slide and bring the edge
of leaf into sharp focus with the low power of microscope. Then
move the slide carefully, keeping the edge always in view.
Vorticella may be recognized by its bell-shaped body, the
ring of waving cilia around the mouth, and by the long coiling
thread which attaches it to the leaf. Larger organisms, rotifers,
Cyclops, daphne, etc., visible to the naked eye, may also be found
in pond water. These make suitable specimens for microscopic
Soft jelly-like masses may often be found on decaying wood
in pond water. These are fresh sponges. Some ponds contain
hydra, usually found on the stems of bullrushes under the sur-
face of the water.
(For several students)
Bacteria are minute fungus plants that are either parasites
or saprophytes. They are widely distributed and can be grown
on artificially prepared media.
Materials: Beaker 400 cc. ; test tubes; funnel; flask; cotton
wool; Petri dishes; burner; water; agar-agar; beef extract; a
piece of cotton.
Procedure: Into the beaker containing about 200 cc, of dis-
tilled water, put 3 grams of agar-agar and about 1 gram of beef
extract. Dissolve the agar-agar by heating the water. Strain
through cotton into a flask and heat again.
Sterilize the Petri dishes and test tubes by boiling in water
for 5 minutes. Pour the sterile medium into the Petri dishes or
half fill the test tubes. Cover the dishes and plug the test tubes
with cotton wool. Rest the test tubes at an angle to form a larger
surface. Allow the liquid to stand till cool and firm.
Set one test tube aside as a control.
Remove the cotton wool from a test tube or the cover from a
dish and expose contents to the room air for ten minutes. Cover
as before and label. Similarly expose other culture media to (1)
a drop of dirty water, (2) a drop of milk, (3) dust from the
desk, (4) your finger. Cover and label. The dishes containing
the drops of liquid should be shaken to spread the liquid. Set the
dishes in a warm dark place.
Examine after several days. Note the number of colonies,
colour, shape, rate of growth. Record your observations. When
a culture is sufficiently developed make an accurate record in the
form of a drawing.
(For several students)
Materials : Saucer ; large beaker ; piece of bread.
Procedure: Moisten a piece of bread. Either leave it exposed
for several hours, or sprinkle with dust from two or three
sources. The bread may be dusted with other mould spores, if
available. Cover the bread with the beaker, and set aside in a
warm place. Examine daily. When growth begins, examine
closely with a magnifying glass, and under the microscope.
Record your observations with diagrams.
Several kinds of moulds may be found.
If you have been successful in obtaining the "black mould,"
place a black sporangium (see page 125 in textbook) on a glass
slide. On it place a cover slide and press gently so as to crush the
sporangium. Now examine under the microscope, first low, then
Additional Experiment on Moulds
(For all students)
Materials: Test tubes; cotton wool; clear fruit juice.
Procedure: Put a few cc. of fruit juice into 2 or 3 test tubes.
Add an equal volume of water. Shake. Inoculate the liquid by
adding a little mould to it, or by sprinkling it with dust. Plug
the test tubes with cotton wool, and set in a warm place.
Observe as above and record your observations.
6. DISSECTION OF EARTHWORM
(For pairs of students)
Materials: Dissecting pan; forceps; scissors; dissecting
needles ; pins. Dissect under water, renewing water frequently.
1. Lay the specimen on board, dorsal side uppermost; stretch
and pin at ends, slanting pins away from the worm. Make an
incision through the skin near the posterior end and to one side
of the dorsal blood vessel. With scissors cut forward along a line
parallel to the intestine until the anterior end is reached. With
forceps, lift the cut edge of the body wall and run a dissecting
needle along the side of the intestine to cut the partitions that ex-
tend from intestine to body wall. Turn the edges of the body
wall back and pin them down, slanting the pins so that they are
out of the way.
2. The intestine is the most prominent organ disclosed. ^ It
is dark-coloured from its contents and nearly fills the body cavity.
3. Along the top of the intestine is the dorsal blood vessel.
4. With a lens, observe the partitions. How do they corres-
pond to the segments you have observed in the external surface?
5. In the first six segments (anterior end) you will find more
muscle tissue than in the remainder of the body. These are at-
tached to the pharynx.
6. On the dorsal side of the second segment you should see
two ganglia, white masses of nerve tissue which serve as a brain.
From these, a nerve cord passes on either side of the pharynx to
rejoin in a thin white thread which extends the entire length of
the ventral side. You may be able to see it with a lens.
7. In the region of the tenth segment are the sperm sacs,
several pairs of white bodies, plainly visible.
8. Lying in segments eight to twelve are the aortic arches.
These serve as hearts to pump the blood. They can be traced
from the dorsal blood vessel to the ventral blood vessel. ' The
aortic arches may be seen best by anesthetizing a living worm
(chloroform or ether) , and holding it up by the extreme posterior
end, swinging it around several times until the centrifugal force
causes the blood to collect in the anterior end. If it is then
opened, the aortic arches will be found distended with blood.
9. When the sperm sacs are removed, you may find in the
ninth and tenth segments two small pairs of white spherical bod-
ies, the sperm receptacles or spermathecae.
10. The ovaries may be found in the thirteenth segment.
11. Trace the alimentary canal. The mouth occupies seg-
ments one and two ; the pharynx, four to five ; the oesophagus, six
to fourteen ; the crop, fifteen to sixteen ; the gizzard, seventeen to
eighteen. The intestine occupies the remaining segments.
12. Remove the intestine, noting the ventral blood vessel and
13. Attached to the ventral side of each segment is a pair of
tubes thrown into many loops. These are the nephridia or
14. Examine the body wall under a lens and later with mic-
roscope. The outer layer peels off easily and is very thin. This
is the cuticle. The next layer is composed of circular muscles,
and the third, of longitudinal muscles.
15. Mount a drop of liquid found in the body cavity under the
microscope. The white corpuscles are clearly seen.
7. THE GRASSHOPPER
(For all students)
Materials: Grasshopper; dissecting needle, or large pin; for-
ceps; magnifier; white paper.
Procedure: Examine the general structure of the insect, us-
ing the magnifier as an aid. Note the three distinct body di-
visions. Name these. Draw the grasshopper (side view) and
label the main features.
Head — Examine the head with the glass. Locate the follow-
ing parts — feelers, compound eyes, simple eyes (ocelli), mouth,
palps. With the aid of the forceps, carefully remove the mouth
parts and arrange them on a sheet of paper in their relative posi-
tions — upper lip, lower lip, mandibles (hard, black jaws), maxil-
lae (bearing palps), tongue.
Make a diagram of the mouth parts as arranged. Label each
part. (Diagrams of mouth parts may frequently be found in
Thorax — Note the shape of the thorax and its three seg-
ments (prothorax, mesothorax, metathorax). Note the number
of wings, their structure and shape. To what segments of the
thorax are they attached ? Compare the under wing and the top
Examine the legs and note their insertion on the thorax.
Hunt up in a reference text the names of the different segments
of the leg.
Abdomen — Count the number of segments. Locate the spir-
acles and count them. The ear of the grasshopper can be easily
seen on the front segment of the abdomen above the insertion of
the large jumping leg. The end of the abdomen of the female is
modified into an ovipositor or egg layer.
Using a sharp knife or razor blade, slice a thin section of the
compound eye and examine under the microscope.
A cabbage butterfly may be examined if desired. A piece of
a wing should be examined under the microscope to observe the
scaly covering. This will be more easily observed if some of the
scales have first been removed by rubbing the wing with the
8. INSECT LIFE HISTORIES
Materials: Flower pots; lamp chimneys; cheesecloth; rub-
ber bands ; soil ; plants or twigs for insect food.
Procedure: Collect insect eggs or larvae. Note the kind of
plant upon which each is found in order to supply the proper
food. Fill the pot with soil. Close the top end of the chimney
with cheesecloth held with the rubber band. Place a young plant
or twig in the soil. Add water. Put the eggs or larvae on the
plant and set the chimney over the plant.
Make daily records of any changes which occur.
The develpoment of mosquitos from eggs can be readily
watched by placing the eggs in a beaker of rain water (or slough
water), setting the beaker on the soil and covering with the
Permanent Life History Exhibits
Suggested exhibits to be made by different groups of stu-
dents are: Grasshopper, monarch butterfly, honey bee, potato
beetle, cutworm, dragonfly, housefly, promethia moth, red under-
wing moth (catocala) .
Cocoons containing living pupae of the large silk moths may
be obtained from the General Biological Supply House, Chicago.
When hatched, excellent exhibits of these may be made, showing
the cocoon (outside and inside), pupal case (in cocoon) and
adults (male and female).
Materials: Riker mounts (or cigar boxes, cotton batting and
cellophane) ; small wide-mouthed vials; alcohol; specimens.
Procedure: Place a few eggs of the cabbage butterfly (the
common white) , obtained from the leaves of the cabbage in early
summer, in a vial. Add alcohol and stopper tightly. Later place
one good sized larva in a second bottle. Add alcohol and stopper.
Repeat later with a pupa in a third bottle. Mount a specimen of
the adult butterfly with wings spread. Do not use a pin in the
thorax. The body may be held firmly in position in the groove of
the mounting board by placing pins against the body behind the
Spread a layer of cotton batting in the cigar box, sufficient to
fill the box. Place the bottles and the adult insect in position on
the batting. Identify each by a typewritten label. At the bot-
tom of the exhibit place another label on which are shown the
names (scientific and common), date collected, etc. Paste the
sheet of cellophane over the box. The sheet should press lightly
on the specimens. Riker mounts are more satisfactory than
cigar boxes, but also more expensive.
9. CLASSIFICATION OF INSECTS
(For all students)
Materials: Several specimens of insects, including some of
the following : Housefly, grasshopper, moth or butterfly, bee, dra-
gonfly, potato beetle, stink bug, mosquito.
Using the following key, classify each specimen :
With two wings only Diptera
With four wings —
Outer pair of wings hard and shell-like... Coleoptera
Outer wings with the front half hard and the
rear half membranous Hemiptera
Wings much alike^ —
Both pairs of wings colored; covered with
scales Lepidoptera .
Wings thin and transparent —
Outer wings folded over inner fan-
like wings; held close along body
when at rest Orthoptera
Wings held at right angles to the
Mouth parts for sucking and
Mouth parts for chewing.., Odonata
In your note book (1) copy the "key'', (2) write down the
Orders listed in the key with the name of insects classified in
10. DISSECTION OF FROG
(For small groups of students)
Materials: Frog; dissecting board; pan; dissecting needle;
scissors; knife; forceps; pins; probing rod.
1. If the frog is living, place it in a wide-mouthed jar. Pour
ether or chloroform on a piece of absorbent cotton and drop the
cotton in the jar. Seal and leave for half an hour.
2. Place the frog on its back on a dissecting board. Stretch
the forelegs well forward and tack them to the board. Stretch
the hind legs well back and tack them. With forceps pinch up a
fold of skin near the pelvis. With scissors, snip through the skin
and slit the skin from pelvis to chin. Loosen the skin wherever
it adheres to the underlying tissues and turn it back.
Cut outward from the centre line to each leg and slit part
way along the leg. Pin the skin back so that it is out of the way.
Cut through the muscular wall of the abdomen and carry the
cut forward in the same way as with the skin. Be careful to keep
this cut a little to one side of the centre line and watch the point
of the scissors to see that no internal organs are injured. Tack
the flaps of the abdominal wall.
3. The most prominent organs in the body cavity are the
liver, and, if the frog is a female, the oviducts. It may be neces-
sary to lift or remove these to see the other organs. The liver is
chocolate-coloured and has several lobes. If the oviducts are
filled with eggs they will appear black, owing to the colour of the
eggs; if not, then they appear as long white tubes. They must
not be confused with the intestine.
4. At the anterior edge of the liver and between the lobes is
the reddish heart. It is enclosed in a very thin transparent sac,
the pericardium. Pinch this vip with the forceps, cut through it
and remove most of it. If the frog is freshly-killed, the heart
may be still beating. The main artery from the ventricle divides
into two branches, right and left, and each of these into three sub-
divisions : 1, to the head, the carotid ; 2, to the body, the aorta; 3,
to the lungs and skin, the pulmo-cutaneous.
You may puncture the heart and probe with a blunt wire to
trace the arteries and veins. Later, if you wish, you may dissect
5. On either side of the heart and partly hidden by the liver
are the two lungs. If they are collapsed, they may be inflated
with a glass tube or blowpipe applied to the glottis. Compare
them with lungs of a bird or mammal.
6. Push the liver aside to expose the stomach. Probe from
the mouth through oesophagus to stomach with a blunt rod.
7. At the posterior end of the stomach is the intestine.
Trace it throughout its course. How does it compare in number
of folds with: a fish? a duck? a chicken? or a rabbit?
8. Notice the thin membrane which stretches from fold to
fold of the intestine. This is the mesentery. Where is it at-
tached to the body wall ? Notice the blood vessels which form a
network in the membrane. Where are the capillaries which con-
nect arteries and veins?
9. The pancreas lies in the first fold of the intestine and the
stomach. It has the appearance of a yellow cord with lateral
10. The intestine empties into an organ called the cloaca.
This receptacle receives the wastes from the intestine, the urin-
ary bladder, and also the sperms or eggs from the reproductive
11. On the dorsal side of the body cavity and on either side of
the cloaca is a flattened, reddish body, the kidney.
12. Near the ventral surface of each kidney is the spermary
or ovary, depending upon the sex of the frog. Sperm ducts or
oviducts lead from these to the cloaca.
13. The spleen is a small red spherical body close to the left
14. The thyroid glands may be found on either side of the
oesophagus near the pharynx.
11. CORPUSCLES OF FROG OR FISH
A live frog is enclosed in a small cloth bag with a draw-
string tightened around the hind leg so that only the foot
The bag may be secured with strings to the stage of the mic-
roscope so that the webbing of the extended foot is over the aper-
ture and under the low power objective.
The webbing of the foot is suflficiently transparent to enable
the student to watch the corpuscles flowing through the veins and
An even better view of corpuscles, coursing through blood
tissues, may be seen in the tail of a goldfish or minnow. Wrap
the live fish in a clean wet cloth with only the tail protruding.
Place the tail on a wet glass slide and view under the low power
of the microscope.
Tadpoles may also be used for this purpose, if they are
caught in the stage when they are breathing by external gills.
The circulatory system where it passes through the gills may
easily be seen. The tiny tadpole can be placed on the glass slide
with its gills in contact with the glass.
12. GERMINATION OF FERN SPORES
(For two or three students)
Materials: Culture dish or saucer; small unglazed plant pot,
3"; large beaker; moss (sphagnum moss, if available) ; fern
Procedure: Fill the pot with the moss or some suitable sub-
stitute. Wet moss and pot thoroughly. Invert the pot with moss
and place on the bottom of a Petri dish or in the saucer. Dust
the fern spores (from sporangia) liberally over the damp pot.
Add a little water to the dish and cover with a large beaker. Set
aside at room temperature. These spores may take weeks to
Examine from time to time and when germination begins,
as seen by the green colour, remove a few prothallia to a glass
slide. Add a drop of water and cover with a cover slip. Exam-
ine under the low power of a microscope.
Make a cross section diagram of the apparatus and label.
Draw several successive stages in the germination as seen under
13. STRUCTURE OF MONOCOTYLEDONS AND
(For all students)
Materials: Young stems of plants; geranium, fuchsia, lilac,
maple, etc. ; ink or dye ; razor blade ; magnifier ; microscope.
Procedure: (1) Stems: Dicotyledons. Make thin slices of
stem of geranium, fuchsia, etc., and examine them under the low
power of the microscope. Cut stems of the same plants and of
lilac, willow, maple, etc., with vigorous leaf systems. Place the
cut ends in a jar of dye (eosin, weak solution of red ink, etc.).
Leave for one or two days. Remove and slice thin cross sections.
Notice the tissues that have carried the dye. How are they
arranged? (The wood cells, xylem, carry liquids upward in the
Examine the slices with a hand lens and with a microscope.
Notice the epidermis, the cortex, bast, wood, and pith. The wood
should show the stains from the dye. The bast should be un-
coloured, but should be in the same bundle with the wood and
toward the outer edge of the stem. Cells of pith and cortex are
much larger than wood and bast cells, the pith in centre of stem,
and extending outward between bundles of wood. The cortex
lies outside of the bast and extends inward between the bundles.
The cambium layer is not a part to be seen as a distinctive type
of cell. It is the region of growth, and new cells of wood, bast,
pith and cortex are being formed there during the growing sea-
son. When cells are growing most rapidly the walls will be
weak, and a sharp twist will sometimes separate bast and cortex
from wood and pith. (Every boy has done this in making willow
whistles.) This is a good method for locating the cambium layer.
Stems: Monocotyledons. Repeat the above procedure with
steins of corn, onions, lilies, cereals, dates. Dye rises in the wood,
as before, but the coloured tissues will be found in a different pat-
tern. Bast and wood are still bound in bundles, but these bundles
are scattered in the pith.
(2) Leaves. Collect and compare leaves of monocotyledons
and dicotyledons. Generally speaking the former are parallel-
veined, and the latter, net-veined.
(3) Flowers. Collect and compare flowers of the two classes.
Count the petals, sepals, stamens, lobes of stigma, sections of
ovary, etc. Monocotyledons generally have these parts in mul-
tiples of three, dicotyledons, in multiples of four or five.
(4) Seeds. Collect and soak seeds of flowering plants. Re-
move the testa or outer covering ; the origin of the terms ''mono-
cotyledon'' and "dicotyledon" should be clear. In dicotyledons,
e.g., beans, peanuts, etc., the seeds should divide easily into two
parts, the cotyledons.
14. FOOD CONTENTS OF SEEDS
(For all students)
Seeds contain one or more of the following food materials —
starch, protein, fat, oil, mineral matter.
Instructions for making tests for determining the presence
of any of the above materials may be found in Exercise No. 15
of the Chemistry experiments.
15. IDENTIFICATION OF TREES
(For all students)
During their study of Biology, students should become fa-
miliar with the names and appearance of several of the common
trees and shrubs of the district. The following exercise should
be carried out in the early spring, when the buds are beginning
Materials: Young, vigorous twigs (length 5") of several trees
and shrubs : poplar, birch, maple, Manitoba maple, ash, elm, lilac,
willow, tamarac, pine ; magnifier ; dissecting needle.
Procedure: Note carefully the following features:
(1) Colour and appearance of bark of stem.
(2) Relative position of buds on stem (opposite one an-
other or alternate).
(3) Shape and colour of buds.
Remove one large bud and carefully dissect it, placing the
scales and leaves on a sheet of paper in order as they are re-
moved from the bud. Note the young stem which remains after
all leaves are removed.
Make a drawing to show these scales and miniature leaves.
In your notebook, rule a page aS shown below, leaving plenty
of space for the drawings. Under the headings "Twig'*, "Bud"
and ''Leaf", make careful drawings of these parts. Rule a space
for each plant examined.
16. SEED STRUCTURE
(For all students)
Materials: Bean seeds and corn seeds soaked for 24 hours;
magnifier; iodine (weak solution).
Procedure: Bean : On the testa or seed coat, find the hilum or
scar where the seed was attached to the pod. Near the hilum is
a tiny opening, the micropyle^ which admitted the pollen tube to
the ovule. Make two drawings of the bean, one side view, the
other from above, showing the hilum. Label.
Remove the testa. Note the two cotyledons, held together by
the embryo. Open the two parts, carefully breaking them apart.
Locate the ^niule or little leaves, and the stem or hypocotyl.
Make a drawing and label.
Corn : Make two drawings of the corn seed — ^f ront and side
views. Note the light coloured area — the embryo. Cut the seed
lengthwise through the embryo. Stain the cut surface lightly
with the iodine and note which part contains the starch. Ob-
serve the embryo — plumule, hyprocotyl and cotyledon. Make a
diagram and label.
17. SEED GERMINATION
(For several groups of two or three students)
Materials: Flat wooden boxes; sawdust, sand or soil; bean
seeds ; pea seeds ; corn seeds.
Procedure: Soak all seeds for 24 hours before planting. In
the box, plant 20 to 30 seeds of each kind. Keep the sand moist,
but not too w€t. Dig up a few seeds every other day and record,
by labelled drawings, the successive stages in the growth of the
This experiment may be varied to suit the size of the class.
If desired, a number of seeds may be planted at intervals of three
days, thus giving, in time, a complete series of stages of growth.
One class period would then enable the students to record the
By keeping some boxes in bright light, while others are kept
in a weaker light, the effect of light upon the growth of the seed-
lings may be studied.
In small classes, students (in pairs) may be required to
carry out the entire experiment.
Among the factors to be noted are :
(1) Time required for germination.
(2) First part of embryo to break through the testa.
(3) Part to appear first above ground.
(4) Position of cotyledons in seedlings.
(5) Rate of growth.
MUTILATION OF SEEDLINGS AS METHOD OF STUDYING
FUNCTIONS OF DIFFERENT PARTS
(For several students)
In trays, plant rows of seeds. Sawdust is easier to use than
soil. When germination has taken place and the leaves are be-
ginning to appear above the surface of the sawdust, dig up speci-
mens carefully; from one cut off the cotyledons or remove the
endosperm ; from another remove the radical ; from another the
plumule. Replant all parts, labelling them with distinctive num-
bers or words. Continue to water all specimens. Keep a record
of their subsequent progress. Be sure to leave two or three
plants uninjured as a control.
18. FLORAL STRUCTURE
(For all students)
Materials: A few complete flowers, such as lily, radish, pe-
tunia, buttercup, sweet pea; needle; magnifier; forceps; white
Procedure: Examine the whole flower, noting the different
parts from outside and inside. Cut the flower through the middle
and make a drawing of the parts observed. The base of the
flower is known as the receptacle. On this are the sepals com-
posing the calyx. Note their shape, colour, size, number and
whether they are united or separate. The next envelope is the
corolla, composed of petals. Examine these as you did the sepals.
The stamens consist of filaments and anthers. Examine the an-
thers carefully, cutting them open to observe the pollen grains.
Examine some pollen under the microscope. In the centre of the
flower is the pistil. It consists of ovary, style, and stigma. Feel
Complete the following table in your notebook. Make draw-
ings under the heading ''shape.''
19. GERMINATION OF POLLEN GRAINS
(For several students)
Materials: Petri dishes or saucers; sugar; water; pollen
grains of several kinds of flowers.
Procedure: In 100 cc. of water dissolve about 1 gram of
sugar. Boil for a few minutes. When cooled pour a little solu-
tion into each of the dishes. Dust some pollen grains from the
anthers of a flower onto the solution. Cover and set in a warm
place till next day. Examine some drops of water under the mic-
roscope — first low power, then high power.
Make drawings of your observations.
20. SNAILS' EGGS
An interesting study may be made of cleavage of fertilized
cells and embryonic development if a few mature snails are kept
in a glass jar in the classroom.
Egg clusters are deposited on the sides of the jar. These
may be scraped off with a sharp knife and examined under the
microscope. Sperms may sometimes be detected under the high
power objective, swimming in the water surrounding the eggs.
If taken soon after fertilization takes place, the egg may be
seen going through the process of cleavage. The one cell may
be seen dividing into two, the two into four, and so through other
successive stages, blastula, gastrula until shells are formed and
the young snails are ready to emerge from their gelatinous
envelope to forage for themselves and live their independent
21. WEEDS OF ALBERTA
(For all students)
Materials: Complete specimens of several weeds common to
your locality. Magnifying glass.
An herbarium of weeds should be prepared for every biology
laboratory. These specimens should show as many parts of the
plant as possible, and after being pressed and dried between
large sheets of blotting paper, they should be neatly mounted
on regular mounting sheets, and accurately labelled. Thick roots
should have the back sections cut away. Freshly collected weeds
are, however, preferable for study.
Coloured charts of Alberta weeds may be obtained from the
Department of Agriculture, Edmonton.
Using a full page in your notebook, rule a table, as shown
below. Under the headings— "Leaf ," "Flower,'' "Seed or Fruit,"
make drawings of these parts respectively. Ten or twelve of the
noxious weeds in your neighborhood should be examined.
LB 1629-5 A3 *35 19H6 6R-10-12:
PffiW OF STUDIES FOR THE HIGH
SCHOOL - ^^ ^QQ^^glO CURR HIST
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